In no particular order:
Coral Oasis - They have great stuff for $5 - $15
Coral Gazers - Lots of corals and tons to choose from, and the store is looking much better (even though I go in and rarely buy stuff it's nice to talk to someone who isn't your standard sell stuff and not care business owner)
Tong's - 99% of the time I go in here and walk out with nothing, though on the occasion they do have a rare fish I might like. The only reason I stop here is because it's very close to Coral Oasis.