My favorite gallery in New Haven, the British Art Center is an exceptionally well curated museum. Its permanent collection is impressive, it brings in some excellent traveling shows, and has a great educational program to supplement your experience - great docents (frequently Yale students), occasional film screenings or musical performances, and other innovations.
If you live in New Haven, don't overlook the BAC gift shop during the winter holiday season - they've usually got the most creative/unusual/attractive holiday cards in town, at reasonable prices.
During the summer, remember - it's air conditioned.
more