There are not that many rollercoasters in Norway, so I guess taking up a thrill rides hobby here isn't going to be anywhere as fruitful as it could be in America. The most exciting thing I've been in is this :
It's called Speedmonster and is in the Tusenfryd theme park not far from Oslo. It's quite thrilling and so fast you barely know what's going until the ride is finished. It starts like a bullet and it's all over a bit too fast. I like those that build a little suspense before you're thrown into the rush.
I tried bobsleigh once, though. That was also fast and fun.