Guinness Foreign Extra is my all-time favorite. Not the Guinness Stout, brewed in Canada, that we get here in the States. But the thick dark beers are best in cool weather.
For our summers, which can reach close to 100F, I prefer something a bit lighter. Great Lakes, out of Cleveland Ohio doesn't make a bad beer, but this is my favorite summer beer:
I'm lucky to have some really good local breweries. This is my favorite: