I've played my fair share of MMORPGs, mostly free ones. I've noticed that people tend to flock to certain games because there's a new/flashy feature. What's your MMORPG of choice and what feature about the game do you like the most? The feature doesn't have to be unique or new or drastic.

My example: I enjoy RoM (Runes of Magic) and have been for a while. My favorite feature by far in any MMORPG I've played is the Elite Skills. You basically receive skills as you level up that combine your 2 active classes. For instance, if you are a druid and a rogue as your classes, your Elite skills will be based on dark or poison damage. It's very similar to the DSS Card system from Castlevania: Circle of the Moon except that the skills increasingly alter how your character plays.

A robust, involving but yet simple crafting system with a lot of varieties for the final product.  Cough, Ryzom.

GS