Last note - in our area there are vinyl LP Record obsessive collectors (as well as for books) who wait years to volunteer in the book and record section of thrifts, and then cream off the "good stuff" for themselves before it reaches the floor and then sell it at a profit at other area venues. This is epidemic in Washington DC and made many thrifts useless for book and record collectors.
Do you remember the old yearly Goodwill sale? I used to go with a vinyl-maniac friend...we'd show up hours ahead of time, and the rush for the vinyl tables was insane! Someone once bought a disc off him on the sales floor--a disc he hadn't even bought yet!
It was fun to hang around with those guys, but it did make things difficult for the rest of us. And it seemed like even among the vinyl people the "normal" (ha) collectors had great scorn for the dealers, who were just there to buy for resale.
On to other things: My nearest thrift shop is the Goodwill in Annapolis. It's OK--pretty variable, actually. I'm really annoyed with the staff attitude toward donors; it's turned a lot of locals away from donating and toward Freecycle (also a worthy program, albeit useless for the sort of random browsing I like to do).
I used to like Value Village in Bladensburg, when I lived closer. I was there a few months ago and found some good deals on summer clothing--and also just enjoyed the hell out of looking at T-shirts and housewares for the kitsch factor.
Laurel was wonderful about 10 years ago for Amvets and Village Thrift, but I don't know if they're still there, let alone if they're still as good.
Any recommendations in southern Anne Arundel/northern Calvert (or nearby PG)? Am I missing any must-see places?