Pretty cool that perhaps a majority of the games listed here, I own: Surfer/Surf Champ, Royal Flush/Card Whiz, 300/Top Score, Slick Chick, Jacks Open, Jumping Jack/Jack In The Box, Fast Draw/Quick Draw, Wizard, Domino, Sky Jump, Big Shot, Abra Cadabra, 4MBC, Wizard, etc.
Out of all the games I have, the machine that I might have if I could only have one would probably be a toss up between 4MBC and Card Whiz/Royal Flush. 4MBC is an engineering and artwork masterpiece. Royal Flush is, IMO, the "perfect" pinball machine.
In our club, no EM gets more play than Card Whiz/Royal Flush. It has a very simple ruleset that's easy to grasp, yet extremely difficult to master. It has the perfect balance between requiring great shots and nudging skills, and punishment if you make a mistake.