4x/8x or 2x/8x for the new titles. In FPSs at least, AA can go down to 2x, but if you are looking for prone snipers on a hill side, those jaggies can hurt you big time. You have to differentiate between a jaggy and a player. Which is horrible, hence the 2xAA minimum. Doesn't overblur the edges, and sharpens up the edges to avoid the creeping effect you get on edges without AA.
If I had a choice, I would run AF over AA, if I could bump up the res to compensate. One of the drawbacks of an LCD monitor, the inability to run different resolutions that do not effect the image quality on screen.
I do agree I've been noticing some blurring in EQ2 and WoW, with AA on. I tend to prefer to turn off the AA when I play those. Though jaggies are teh debil.