I've had nothing but good experiences at New World. When i had a tannin problem and i was looking at purigen, they suggested bio-chem zorb and it worked out great. Overnight i had no more tannin problem. They have also been helpful with plants for my 12g eclipse which is hard to stock with the low light. They sold me some wisteria which has been kicking butt. I'm probbaly headed back soon for some more fish. Plus they have the honey gouramis which rule.
Pacific is a good place. I haven't bought much there, but i found their prices ridiculously cheap. I bought my initial 3 zebras there, and one is still alive so I guess their fish are ok. i will probably go there again soon.
I haven't been to Win's. Around the corner eh?
I recently got a 5.5 gallon at a petland when i was buying food for 8 bucks. So i will probably attempt to get all my supplies at either of the two. Though i will head to NW first.