The Wizard of Oz slots are also at Harrah's Ak-Chin just outside Phoenix. On a recent trip, we saw them but all the machines were taken plus there was a crowd gathered waiting to play so we weren't able to play them...again. The chairs alone make me want to try them.

Looks like a big winner for WMS Gaming.
To find favorite slot machines -- if you play at Harrah's properties, go to their website and the "Slot Finder" page to look for games available in their casinos. Also, the ballytech website provides info on where to play their games like "Millionaire Sevens," "Hot Shots" and more under the tab marked "Player Center." Those are the ones I know about.
C.C.