In Las Vegas there are 3 varieties of Superman Slot. Superman the Movie is the most common, which was certainly a hit when it first arrived.
Superman the Movie Slot
Superman is an aggressive slot, you can spin endlessly with few wins that exceed the bet-size. It is one of those machines that is all about the feature of getting 3 bonus superman symbols to gain the chance of a minor or major bonus. We have never seen a major bonus, but had a couple of minors when the game first appeared.
Superman Slot

The Superman the Movie slot isn’t quite as popular as it used to be and there is a replacement called Superman 2 which is making an appearance now, which is almost identical in it’s aggressive nature and offers the Zod feature bonus. Here are some images of Superman 2.
Superman 2 has a nice little random feature that pops up on occasions if you have a no win situation. The screen says ‘No win this time, but Superman comes to save the day’. Superman flies across the screen and delivers a couple of wilds and the reels go into a remix for 3 free spins. This delivers a few dollars and breaks up the humdrum of spinning with no wins.
Superman2 Zod

There is another Superman slot that i have only noticed in Bellagio which is seemingly off the scale in aggressive-ness and encourages a player to play very large bets per spin. I have tried this machine a few times at 50c and i dont think i got anything back at all. It is called Superman LL and the reels are comic-book style.
At first glance it looks a bit of a cheap machine, but it is actually 2 machines in one, you can play the Lex Luthor version where the machine turns green, however the bet costs range from $5-$25 a spin.
Superman Lex Luthor