I am really into pinball games.
Some I really like are Flipnic on

, Devilish (I know its not a true pinball, but anyways) on Genesis, Game Gear and DS - I like the Game Gear version the best. Likewise, I think the "Crush" series is excellent. I really want to like Flipper Critters on DS, but its sort of frustrating to play. Virtual Pinball for Genesis is neat for a little while. Oh... Crue Ball on Genesis! That game is pretty sweet and especially if you like the arena rock! Metroid Pinball on DS is okay. Pinball on NES is always good - I think it was even an unlockable game in Animal Crossing for Game Cube. Dino Land for Genesis is somewhat frustrating to me but fun.
For PC, I really like Microsoft's Pinball Arcade - tables based on real tables.
Another really cool one is this freeware game made by a Japanese guy released under
Yamada No Ana Project. Its a Slot Pinball machine and I've played way more times than I can count. The website is in Japanese, but if you play it, the game is in English and very easy to understand.