Jilly's is great! Cheapest pinball around. This is probably the best time to play their games though, since the techs have more time to tune them up before the summer rush. If you've ever gone there in the middle of the summer, it's disappointment city--Especially that Monster Bash they have with the kickout hole that's been worn to the size of your fist. Still, at 25 cents a play, I hardly complain.
There are a couple other arcades with some well maintained games farther down towards Gilligan's Pier. I can't remember the name, but they have an Indiana Jones, Batman, and a couple of other neat seldomly seen games. One of them has a Funhouse and Jacks Open way in the back.