I think skill level and time on a machine impacts how you feel about it, and with some cases, the world in which you first played it, sentimentality is a big part of pinball, both games and themes. Some games require a higher level of skill to 'get it'. A lot games are great on location where you playing just a half dozen games, the layout, the theme, the sound, the toys can all create a fun experience. The more you play a machine, the more you explore the rules it either clicks with you and pulls you in further or leaves you feeling "its okay". Some games, require a sufficient amount of time and an good understanding of the rules to 'get it', TSPP was a game like that for me, first few times I played it, I did not get it. Once I took some time to understand the rule concepts, the game clicked for me. The more varied games you play, the more you will grow to appreciate games that you may not 'get' the first few times you play them bit there will always be games that just don't register with you.
as far as a couple mentioned in this thread . . .
Rudy is a great toy, but don't get the love for funhouse. Not saying it is a bad game, and I have played many a game on it, but seems to get a lot more love that I would give. But I guess the humor of an evil puppet is something folks connect with. And anyone who has spent time on Houdini or Oktoberfest knows I like insulting the player.
Williams Indy -- cool game, I'll play it a few times when I see it, but have had no interest in owning it, never gave me that "game over . . . must hit start button again" feel. I've always found the playfield feeling crowded with shots too many shots too close to the flippers.
It is great that location play is continued to improve. Lots of games to enjoy on location and you don't have to fully 'get it', you can just shoot and enjoy. Seems like a lot of new games on the horizon and glad I have a location nearby that typically gets most of the new releases.