I currently use Vegas 6. There's a 60 day trial that you can use if you wanna test it out, but the retail price is around 400 buckaroonies. I'm sure that, since 6 came out you can find version 5 for cheaper. I didn't really see much of a difference there, though.
I had problems with WMM freezing up when I used it as well. :p And I like Vegad better because I can insert one video clip in the middle of a song and have NOTHING else if I wanted to! BWAHAHA!!
Ahem...
But yeah, that's what I use.
ETA: Erm, I forgot to link to Vegas first time 'round. Whoopsies!
Vegas 6 And I scoped out a bit around Ebay, and it seems you can buy just Vegas 6 for about 200...