Spring Street Spirits has the best selection in town, in my opinion. He doesn't stock a huge number of wines, but everything he does have is carefully chosen. Ask the owner about a wine, and nine times out of ten he can tell you about it. He'll also help you choose based on what you're having for dinner and what you want to spend.
Pros: Great wines
Cons: Not a lot of cheap stuff, if that's what you're into