I don't have one favorite beer, but I would say that I tend to prefer malty beers like porters and stouts. There's nothing better than a rich, creamy, perfectly carbonated (or nitrogenated) stout to go with a satisfying meal; they can even be used as quick snacks by themselves! I've recently started brewing my own beer, and I plan to focus on porter and stout, experimenting with the various malts until I come up with something really tasty.
I tend not to like aggressively-hopped beers, but if the blend is right and they don't go too overboard, I like hoppy beers served with spicy food. A local bar at Virginia Tech has wing night on Wednesdays and Sundays, and the Blue Moon pale ale strikes a good balance with me and helps wash down the hot wings.
So what are your favorite beers?