I haven't had contact with him in years, but I feel that Alan Hamerstron at Interyacht can be recommended without qualification. I have chartered twice from him, and oredered a new trawler to be built through him. I believe that they do strictly brokerage now. I found him to be a man of integrity that will do what he says. All were great experiences.
Long time ago, we dealt with Neal Barrett from YachNet, and he was excellent.
More recently, we talk with various local Knot 10 guys, since they usually bring some beer to our annual owners club party No actual "brokerage" experience with them, though.
Also recently, I expressed some interest in a boat Walczak had listed.. and the broker I spoke with was very helpful. Didn't go any further than that, but I now qualify for the e-mail list and I at least take that for diligence. Later, they had a boat like ours for sale and I looked at it during the Annapolis show, I mentioned it to the owners club, voila, they got a sale and we got a new club member.
I have had great success, and in the mid-Atlantic area would personally only deal with, Trey Schaefer, at Coastline Yacht Sales. I've found him to be totally straightforward, no-nonsense, honest, and just a pleasure to deal with. He's based on Baltimore, but that might be close enough to Annapolis for you.
I second Annapolis Sailyard. Scott and Cary are fine brokers. I have purchased a boat from them and they are first class. Located in Annapolis Harbor.
Slowpoke