I strictly play real time combat MMOs. I love PvP if it's fair and balanced. I hate the rock-paper-scissors aspect of most MMORPG combat. I believe combat should be up to player skill (defined as faster reflexes and a better working knowledge of the games mechanics). I hate grinding for loot drops. Blacksmithing is the only way I want to get my sword!
I play a really fun MUD, the roleplay is really fun because it's a smaller community (300 - 500 players online). The combat mechanics are intensely fun.
In these screenshots I am playing my Serpent character (they are a thief class that can summon pet snakes). I backstab someone, and order my pet snake to begin attacking them.
The person starts to attack me back, and has their sword covered in venoms that give me the Stupidity affliction. This makes my commands do random things instead of what I tried to do. You can see that I am trying to eat goldenseal, an herbal remedy for Stupidity, but it doesn't work on the first try.
They then proceed to slash me again, this time with a venom that gives me Paralysis me. I have to eat bloodroot to cure this one.
The combat is very fast-paced, in real time these things are happening in seconds. You have to out-strategize your opponent and think of what he's trying to do and what you're going to do next. If an MMORPG doesn't have real time PvP, I won't play it!
Screenshots: Achaea a free to play MMO