Currently drinking Heavy Seas: Dubbel Cannon.... everything they make is awesome, can't wait to get down to Baltimore and tour the brewery someday, has anyone done this?
Used to do their tour all the time when it was free and you could get as many samples as you wanted. Now they charge 5 bucks for the tour and they give you 5 or 6 drink tokens. Still a good deal, but not as fun as it used to be. Their tours have gotten quite popular and are almost always very crowded. A friend of mine is brewer for the company so I can pretty much go over there for a "tour" whenever he's working.
I still love Clipper City Brewing Company (still their name, even though their beers are Heavy Seas) but for me now my favorite Maryland Brewery is Evolution. Clipper City is too worried about making as much beer as possible right now where as EVO is expanding slow and steady.
I've seen some posters mention IPA's. I used to like these and Double IPA's alot more but I drink them less often these days. To me it seems like too many breweries are just worried about making the hoppiest beer possible.
As far as Summer Beers go I won't list any specific beers, but some of the styles that I enjoy more in the summer are Hefeweizen's, Pale Ales, Wheat's, ESB's and Weizenbock's.
I know some people will only drink certain beers in certain seasons, but I'm not one of them. If it tastes good I'm going to drink it.