The SkiGym simulator looks like it's going for realism rather than the silly fun offered by the Wii, but some people probably want an accurate depiction of brief exhilaration before the inevitable faceplant.
The SkiGym hooks up to a PC to use the included game Alpine Ski Racing, or it can be used as a standalone gym. The game includes 32 different courses from 18 real-world mountains, just to add to the realism. It's available for a bank account-crushing $US2300, which if I'm not mistaken could purchase a pretty sweet ski trip, but if you're loaded and scared of crashing, give it a look. [Random Good Stuff]