We don't take much credence in the IPDB statistics.
Gottlieb made a lot of great em's. You can have 10 guys in a room and they'll all have a different favorite game. If you search the archives of Pinside or rgp for the top ten Gottlieb em's, that should be a pretty good indicator. Most guys go for the best playing games which have a great theme, great artwork, and most important, a great ruleset. Single player wedgeheads tend to have better rulesets than multi-players although games like Jack in the Box, etc., can be the exception. Having drop targets reset during a ball and not when the ball ends is an example. Several single-players have "progressive" rulesets where you achieve a goal such as 1-9, etc.. Multi-players can't carry features over from ball to ball like single players can. I'm not saying multi-players aren't still fun to play because I own some too.