I don't know who's the best with exclusives anymore either...
Hasbro totally fumbled the ball with the 501st Trooper...
TRU has baffled me on the HFG pack, when they'd had an otherwise stellar track record, even in 2005 when stuff was hot, hot, hot.
Wal-Mart's always been hit and miss... The only exclusive I recall hitting them in droves was the Cantina sets while everything else was either average or downright tough to find.
Target you have the computers and if you have the right routine on it you can track it down, but they're a storre known for screwing the collector on both price and availability at any given turn.
K-Mart actually got lots of their battlepacks in, but while KM is still a big player in the NorthEast they really haven't got the foothold other places and in some they simply don't exist anymore so I don't think they're the best outlet... Plus their pricing was Target-ish here recently with dramatic price hikes when they saw something sold well.
KB... I almost even forgot about them. They never get anything good enough to look for hard anyway.

WM getting an entire wave is just disturbing, repaint or not... What sucks is it's got that Astromech in it and that's one I really want... I could probably not get the others and honestly not care though I'd have a nagging feeling about Sing missing in my set... The Droid I actually want though. blah.