Just did a 120 mile, 6+ hour circuit of some of the ones on the list (and one that wasn't) and thought impressions of them for the out of towners might help. Now keep in mind I mostly am interested in SA cihclids, CA cichlids, and West African cichlids ... but I did try to look around for more than just what I was after.
Denny's Pet World - Kirkland
Solid as always -- They often don't get exotic stuff in, but it's always a good selection with usually healthy fish. Right now there are a bunch of tanks on clearance as well.
Sierra Pet - Factoria aka Bellevue
Skip it --- While never big, sometimes that had some unusual stuff in that made it worth the stop. Lots of the fish were dodgy at best health wise.
Sierra Pet - Renton
Up and coming --- This used to be one of the best stops in the early 2000's, but kind of fell off. The new owners seem to be doing a good job in bringing it back. Lots of neat and unusual stuff, though mostly smaller species. Still some future monster gems though. Nolan there was very cool and we chatted quite a bit.
A Place for Pets - Burien
Beyond perfect, as always --- Lots of monsters, lots of CA/SA/Westies ... and Kevin was awesome as always. Plus has Mick Kelly Irish Pub next door. Great grub and even better beer!!!
The Fish Store - U District
Pretty Good -- Often not mentioned on here due to lack of monsters, still it has lots of dwarf cichlids and assorted oddballs and some gems (True Parrots and C. similis came to mind). Also better plant selection than the previous ones.
Pet-Pourii --- Everett
Very Good --- Lots of monsters, decent new world cichlids, lots of plants.
Bridges Pet - Snohomish
Decent - No real monsters, lots of usual stuff but mostly smaller fish like labrynith fish.