I'm interested in starting to edit videos and I'm looking for a good video editing application. It shouldn't be too complicated but one should be able to do advanced stuff with it too. I currently got iMovie but it's too simple for me.
IMHO with imovie you can achieve NICE results, especially, when you starting to edit.
iMovie has several very nice features (some are not obvious at the first look), and probably you still do not discover them all.
Using professional applications like FinalCut and so on, i'm not recommending for someone who starting to edit. But, opinions are like slaps - they're always different. :)
Maybe, can you be more exact - what feature you missing from iMovie?
As iMovie (surprisingly capable and free) and Final Cut Pro X (extremely capable and not at all free) have already been mentioned, I'll just point out the two other common answers: