I went to Blockbuster's once, the day they released Star Wars: The Phantom Menace onto DVD, because it was late, and they guaranteed me a copy through some promotion. Well, it wasn't filed under S for Star Wars, or P for Phantom Menace, and the stupid kid at the counter had no idea what I was talking about. So I walked out in a fit of seething rage and went to Tommy K's in Branford. I've never looked back.
Tommy K's has a great selection of movies, with extensive collections of both foreign films and various cult classics/indie films. But best of all, the kids who work there know their stuff. They know/appreciate a wide range of movies personally, and they know their catalog, so they can help you find what you want. I've seen them recommend off-beat children's flicks to exasperated mothers, and troma films to bored teenagers, one after the other. They're great. High turnover (as is common in afterschool jobs), but they're consistently great.
If you're in the area, it's worth passing whatever chain stores entice you with dvd promotions to get to them.
Note: about once a month, they sell their used DVDs, usually 3/$20, occasionally less. At prices like that, it's worth building your own collection. (sidenote: if you get to know the cashiers, they might let you peek through the dvd's they've held back to put out when stock gets depleted during one of these sales)