A pretty, historical town, with a couple of excellent brew-pubs and an interesting downtown to walk about in.
I just spent a good part of last weekend here with a friend, staying in hotel (Ships Harbor Inn) near the San Juan Ferry, and exploring the area. The weather was excellent, Anacortes was holding a waterfront festival (which was hokey enough to be fun) and the restaurants and brew pubs were up to their usual fine standard.
Normally, I've just stopped in Anacortes for a few hours, and this was my first extended visit. Its a pretty, low key, and accessible place, with a lot of things nearby that are worth seeing.