Well, my favorite beer....I guess that would really depend upon your definition of a beer, which is a matter of opinion so here goes. I see Coors Light,Bud, Miller, etc. as more of a fizzy drink like a soda that I would have with pizza or something, so when I'm just wanting something like that and not necessarily wanting an actual "beer" I'll go with Coors Light as my go to.
It's hard to decide though, but usually I'm seen with a stout or a fuller body beer of sorts, and sometimes with a trippel or barleywine. My favorite type so far though year round would have to be a coffee stout. A good real stout is usually made with dark roasted malts/chocolate malts so they usually already have a bit of a coffee smell to them, so why not compliment the taste of it and make it with actual coffee. This to me is a match made in heaven! My favorite coffee stout is The Uncommon Stout made by a local microbrewery around where I live located in Moline, Illinois (US) known as Bent River Brewery. As a side note though, most beers made by Founders are really great (and usually have the alcohol content of two "American Lagers"). My favorite by them so far has been Backwoods Bastard, this one's aged in Bourbon barrels and tastes just like bourbon whiskey.