If you ain't afraid of no ghost and you like pinball then Ghostbusters Pinball is worth a look.
This free-to-play game makes good use of the license, delivering a board that's full of features, sound effects, and artwork based around Ghostbusters. Physics are OK, but still not a patch on Zen Studio's creations (Walking Dead Pinball, e.g.).
A word of warning: Ray Parker Junior's classic theme song gets overused in the game, and even hard core fans may get annoyed by it!