I asked that same question once, and ended up starting a side collection just of these chips. There are:
Bettendorf
Biloxi
Blackhawk
Boonville
Bossier City
Kansas City
Lake Charles
Lucaya
Lula
Marquette
Natchez
New Orleans (hard to come by!)
Tunica
Vicksburg
and the Pompano race track ones.

Some cities have two racks (at least)-- an older one and a newer one.