
My first recommendation is to get the PSN version of Pinball Arcade. The controls work slightly better on the XBLA version, but they seem to have stopped supporting it after only adding a few tables .
After that, I really like Attack From Mars, Cirqus Voltaire, Creature From the Black Lagoon, Theater of Magic, Elvira, and Big Shot for non-Williams tables. Unless you're really into excessive tweaking, the Pro versions aren't really worth it.