The Wine Source has a top notch selection, but also has an incredible staff. (If you call ahead, they'll actually save things for you behind the register).
Wells: Not so much so anymore. they have a great selection, but how long have some of those beers been on the shelves.
Beltway: Good for buying mass quantities. You have to get there quick for seasonals, as they disappear fast.
State Line in Elkton: Joining the club allows for a 10% reduction in singles. The owner and some of the staff are beer nerds, which helps.

I go to Ole Federal Hill liquors, which I think has the best selection in the neighborhood.

I just bought a six pack of Sierra Nevada Celebration from there a couple days ago.

Great idea for a topic. It's tough to find many places with a decent selection of good craft beers.

Grand Ritchie Liquors, on Ritchie Hwy next to BJ's warehouse club and Ollies. (Just south of Jumpers Hole Rd) They have probably the best selection of good craft beers in the Glen Burnie/Pasadena area. The owner and staff are very friendly, and the prices are on par with what you'd expect to pay.

A close second, is Cristos, in the Linthicum/Ferndale area. It's on B&A Blvd, about a couple miles west(?) of the beltway, between the Burwood Plaza and the Ferndale light rail station.

While their selection isn't as varied as Grand Ritchies, they come pretty close and they also order kegs of good beer too, (i.e. Clipper City, Sierra Nevada, Dominion, Troegs, etc). They're also a friendly bunch and the prices are reasonable.

To a lesser extent, The Ocean, in Glen Burnie,(B&A Blvd, near the rt 10 exit across from Marley Middle School), is another one.

They're selection isn't as extensive as Grand Ritchie, or Cristos, but they have an ok inventory, and good prices. I did, once, get a skunked 6-pack of Dogfish 60 minute IPA, but that can be caused by a variety of factors, not necessarily the fault of the store.

The owner and staff are very friendly. While I haven't ordered a keg, yet, he did tell me that he could order anything that I want.

After the Barnyard closed on Crain Highway in Glen Burnie, I began going to Dawson's in Severna Park. They know their beer & wine (they have a pretty good wine selection as well) and can order anything for you. Doesn't hurt that it's only about 10 minutes away from my house too!

I was in Frederick about a month ago and stopped at a place called Ridgeway (is that what the place was called??) and they had a nice craft beer selection too.

1.great selection of craft brew,not huge but all winners,and this is really silly,but the name escapes me,small place near lake and falls in baltimore,nice couple owns the place and they have an old citeron(spelling)parked out front.
2.cranbrook liquors in westminster,maryland.
nice selection and the wild goose is super cheap.
3.wine source-probably best in town.

I will go up to the Wine Underground off Cold Spring, side alley place that has a good selection of beers to go along with their wine. The people there seem to know a bit about the beer as well, always a plus

The stores I go to in Westminster, College Square Liquors and Cranberry Liquors, always have a great selection of craft beers including seasonals.

I can pretty much second all of the above. I believe the Citroen place mentioned above is The Old Vine on Falls Road?

The rule of thumb is that if you can't find it at Wells or State Line, you aren't going to find it in this region at all, period, at least not legally through proper channels. Wine Source is giving Wells a good run for their money as well, and has a better selection of sake for those into that. As for the freshness of inventory, that's a legitimate concern anywhere one goes, but Wells does clear out "old" inventory--by return or discount sale--pretty meticulously. At least you're unlikely to find a non-vintage beer that hasn't been made for four years by a brewery that hasn't existed in three, as I did one time in Michigan.

Not mentioned so far: Astor Liquors in the Laurel Shopping Center, and Burtonsville Crossing at Burtonsville (Rt. 198 and 29)--though the latter is in Montgomery County and suffers as a result. Further south, Chevy Chase Liquors in the town of the same name.

I would be remiss if I didn't nominate the tiny, claustrophobic Carpe Vinum, located across the street from the Phoenix Emporium and B&O Station at the bottom of Olde Towne Ellicott City. Great selection courtesy of Bun Penny's former beer buyer. If you need a better selection in that area, Jason's on Rt. 40 west of Rt. 29 is your place.

Jason's on Route 40 in Ellicott City always has a good beer selection, especially Germans and Belgians.

ok from the other day.
the name of the best place(IMO) to buy beer is "the old vine"
not the largest selection of craftbrew and imported beer(see wine source for that)
but a great selection where all are winners!!!! and the staff is friendly.

I like the Harford Beverage Company (connected to Racers Pub) on Harford Road at Taylor.
In Annapolis, the best place to go is Bay Ridge Wine and Spirits, a veritable supermarket of wines and good beers.

Honeygo Wine & Spirits in Perry Hall has a good selection. You can always find some new things.

Beltway has a nice selection.

Max's on Broadway - I always stick to the huge selection on draft. But sometimes I see bottles there that I have never seen before. So I like to grab some to go.

I find that Lyndwood Square Wine & Spirits in Elkridge has a decent selection of beers. They also try to keep a few different variety packs in stock as well as offer a small make your own six pack selection.

I've been going to the Wine Source for years and recently moved about 2 blocks away from there, which makes it nice and convenient. It is a greatn place, but I'd like to see them change up their (cold) beer selection a little more often. Seems like they've always got pretty much the same options.
Another good place is Cranbrook Liquors in Cockeysville. They have "Dollar Days" in the spring and fall where almost everything in the store is sold for a dollar above wholesale cost.