One word....
Guinness. My hands down favorite, but it's gotta be either a draft or draught. I don't care so much for the stout.
As far as other beers go... Penn Dark is pretty decent, Mad Anthony's Ale is an interesting one (dark beer with caramel in it, really pretty good), and Yungling Black and Tan isn't bad (the only yuingling beer I'll drink unless it's free and I'm half drunk).
Killians Irish Red is pretty good too.
Then we get into the lighter beers... I drink a LOT of MHL and Busch, Busch out of a can (pounders baby!), and MHL on draft or in a bottle (MHL just doesn't taste right out of a can). Beyond that... MGD, Labatt Blue, Coors, (I'll drink Coors light if it's free and theres nothin else), Rolling Rock (not a fav, but I'll down it), Iron City Light, I can usually choke down a couple cans of American Light if I get primed on something else, and probably one or two others I'm forgetting. I'll drink Bud Light if it's free. I can't choke down regular Budwiser, I've tried before, had to dump out a full can cuz even drunk I couldn't stomach the taste. I'm not even going to try regular Iron City though, I've been told it tastes like rusty river water.