Make a character on one of the following servers:
Skull Throne, Badlands, Red Eye Mountain, Karak - Azgal, Darklands

Skull Throne - Core US - 10 vs 10
Badlands - Core US - 11 vs 10
Red Eye Mountain - Core US 12 vs 10
Karak Azgal - EU - 11 vs 10
Darklands - Core Oceanic - 11 vs 10

EDIT - Raztor: " I would recommend people to play the class they find fun and enjoy playing . . . "
I also recommend the same thing.  It is important to take population balance into consideration when choosing a side though.  As an Order player, you don't want to be vastly outnumbered, but you can be happy and even benefit from being a little outnumbered.  So choose a server that has 10v10, 11v10, or 12v10 is just fine.
As a destruction, it is more important to choose a server with 10v10 balance or at least 11v10 balance so that you have enough targets, oRVR is competitive, and scenarios pop with an enjoyable frequency.

I recommend playing Order.  If you decide Destruction, you should choose one of the 10 v 10 servers.

The reasons why and some data follows:

Why should I play Order?
    Order is almost without exception less played at all levels and on all servers than Destruction.  On average, there are 13 Destruction characters for every 10 Order players. On some servers it is much worse, on others it is a little better. 
    By playing the less played realm, you promote balance between the two sides (a perfect world would have 10 Order players for every 10 Destruction players).  This allows equal teams when it comes to open RVR (oRVR).
    What's in it for you? As an Order character you will be able to join Scenarios faster than Destruction characters. However, when it comes to oRVR you will be at a disadvantage number wise.  On the servers I recommended, it is very small, even negligible. But on some servers, it could be as bad as 10 Order vs 30 Destruction (Galrauch)!
    As a plus, when balance changes come out you can expect, pound for pound, 1v1, to be slightly better than your Destruction counterparts.

What about Destruction?
    A lot of people like to play Destruction.  The classes look better in my opinion.  If you are set on Destruction it is important to expect longer times to join a Scenario (more people make Destruction Alts than Order Alts).  You will have a few extra team mates when it comes to oRVR though.
    Keep in mind, Mythic has said that when it comes to class balance, they will balance the realms first, then the characters, and then adjust PvE to match the character's strength. If Destruction outnumbers Order during balance changes, there is a chance that 1v1, pound for pound, an Order character will outmatch you to make up for those 10 vs 13 fights.

Why did you choose these servers?
    I ran with a number of criteria through a site called Warhammer Online: Age of Analytics. The following is a quote from that site's FAQ to explain where the numbers come from:

Why did you decide higher population was better than medium or low?
    In PVE games of the past, medium or low population servers were my first choice to prevent overcrowding content.  In Warhammer, the way the quests work (on most, every wolf has a paw) and the fast respawn of mosters; this is much less of an issue.
    When it comes to RvR, more is better.  You want lots of people to play with.  Scenarios pop up faster, more people to get oRvR warbands going.  Life is just better on a high population server.  And since they raised the server caps, you should never run into a waiting period to log on!

What other thoughts do you have?
    I played on a low pop server that transfered to a medium pop server (both are not on my recommended server list) as Destruction.  I also played on a medium pop server (also no on list) as Order.  After rolling Order and Destruction on my recommended servers, the difference is night and day.  The populations and activity remind me of the first week of play.
    I recomend anyone getting frustrated with thier server to give these servers a try.

    In Warhammer, I see some problems, mostly population.  There are to many servers.  I also wish they put more in for oRVR.  One of these you have control over, roll on a high pop server.  The other, they say are in the works, and I hope they are.  I am enjoying this game.

    Server pops will either hold steady or slowly decline until they come out with patch 1.1. After that, they should hold constant and maybe increase as those who left come back and give it a try.  Hopefully they put out a trial at that time also to get more people on board. 

How can I help?
    WOW! You read this far?  Thank you!  I put the important stuff at the top for those looking for a quick answer.  At the end is where I ask you for help.  If you could just reply with some information about your server.  How active is it? What side do you play? What tier are you in? How are the guilds? oRVR? Using the census addon, how many people are on at peek? Off? And any other information you have!  Once I get a few vouchers, I will add that to this post so people can see both hard data and personal observation.  Feel free to include your guild in the post!

Edit:
12/20/08 Formating updates to prepare for content update
11/29/08 Changed intro to reflect types of servers.
12/01/08 Added comments about class choices, added section about vouchers, edited some font.

i chose skull throne and im glad it did. sounds like from threads it is one of the only servers that isnt a ghost town.

I'm there and loving it as well.  Wasteland and by transfer Vortex had ok pops. . .

But I have been in 3 failed keep captures and 3 successful keep captures in the past 2 days, TIER TWO!

Just a lot of fun playing the game as it was meant to play. oRVR with lots of people.

 Or better yet, don't start a character at all now.  I wouldn't start another one now -- leveling through the lower tiers would be so boring now.

meh, when you have active open rvr by tier 2, its fun for me.  But, if you already established on a server you like, no point in switching.  This is more for people who either don't have a server yet, or don't like their current server.

 Very nice post regarding which servers to play in (Sticky maybe?). However I would recommend people to play the class they find fun and enjoy playing, not the side they should be playing for due to population imbalances, that is Mythics problem to solve not the paying custumer.

Dark Crag is a kick ass server.  Some of the top players on destruction were also top players in WoW's pvp scene on Tichondrius, in the Bloodlust battlegroup.  Also, many players on Dark Crag are also from the Rampage battlegroup which is considered the second best battlegroups.  You will also find MANY players coming from the Stormreaver server, which not only houses many great guilds, the most impressive being Impervious, but also many other top pvpers on both horde and alliance. 

Dark Crag was basically the place where many people tired of WoW rerolled.  However, unlike many other players,  these people did their homework and realized that the purest form of competition would be found on an Open RVR server, and thus Dark Crag became their home.

Imo your info is a bit outdated...

Since the EU server transfers started Karak-Norn and Karak-Izor (both Eng)have become very viable. They're both med/med now but still retain xp/rp buffs as an incentive to move there.

I play on Karak-Norn and it's been really hectic this past week. Open RvR is alive and well and there is no problem with finding groups or people in general. I heartily recommend it to new EU players.

The other day I rolled a Runepriest alt and was shocked with the amount of players in T1. I suppose most are alts like me but I met a few guys who were former destros from other servers. What's the situation in other tiers I honestly don't know but T1 and T4 are very alive right now.

Originally posted by markoraos

Imo your info is a bit outdated...

Since the EU server transfers started Karak-Norn and Karak-Izor (both Eng)have become very viable.

The other day I rolled a Runepriest alt.

Hey Markoraos!

Thank you for the reply and the information about those servers.  I've contacted the analytical site's web master about when his next update will be (seems he updates once every week or two).  The date I'm going off of is November 20th update.  Now I use Tier 4 numbers, so they should be insulated for right now against most alts.  Another month or so and we'll have to start using level 40 as the benchmark.  Either way, looking at the data on your own should still tell you what servers not to roll on.

Looking at the data pre merge for your server, I would never recommend anyone roll a character there.  Lets hope the post merge numbers tell a better story!

Originally posted by Raztor
Very nice post regarding which servers to play in (Sticky maybe?). However I would recommend people to play the class they find fun and enjoy playing, not the side they should be playing for due to population imbalances, that is Mythics problem to solve not the paying custumer.
 

Hey Raztor!

I agree people play the class they find fun and most enjoyable to play.  I find the mirror classes are close enough that if you've played a Black Orc you'll be very comfortable jumping into a Swordmaster.  They are different, but the mechanic has the same principle behind it and thus the play style is similar.  The same can be said behind all the classes.

I'm not saying there are no differences in play style, just that the basic mechanic is the same.  The biggest difference IMO is the looks; and to some people that's the deciding factor.

I will update the original post making your recommendation as I share the same view.  But if you don't care that much about looks, I contend that Order gives the better RvR experience on server with 11 or 12 vs 10 population.  On servers with 10 v 10 population it doesn't matter which side you choose.

 

Originally posted by Raztor

 Very nice post regarding which servers to play in (Sticky maybe?). However I would recommend people to play the class they find fun and enjoy playing, not the side they should be playing for due to population imbalances, that is Mythics problem to solve not the paying custumer.

Oh, forgot to add:
I also agree that it is Mythic's job to balance the populations, not the paying customer.  However when deciding to choose a server to play on, population balance should be part of your server choice.  It would be foolish to roll a destruction character on a server where they outnumber order 3 to 1 when you could have rolled on a server where they are equal in proportion.

Updated the main post to reflect new population changes.