Here's a list of some suggestions on good beers many have offered.
Try one of the Belgian offers that are usually available at Cole ave. and even spring street:
Hoegaarden Witbier (white beer) 5%alc. Blanche de Bruges (white beer) Duvel (golden ale, absolutely amazing) 10%alc. Grimbergen Tripple (abbey/trappist ale) Lindeman's Lambic ale (flavored with cherries, peaches, etc.)
If you hate the Belgians, here are some other great brews (available at Spring st.):
Samuel Smith - the whole range: Oatmeal Stout, Imperial Stout, Taddy Porter, Pale Ale, Nut Brown Ale, Winter Welcome Ale. Unibroue Le Fin du Monde Celebrator Doppelbock Stone Imperial Stout
Otter Creek is absolutely fantastic. I especially recommend the Vermont Lager, but all varieties are very tasty.