Womble Video Wizard DVD. Great for resynching audio.

I like to lay out both tracks at the same time (the source one and the one I'm trying to sync), listen for desync between the two, slide around, cut and tweak, or whatever as needed and output nearly untouched 5.1 ac3 track.

I've tried Vegas (briefly) and found it complicated. Womble is pretty intuitive (I learned to use it without instructions and created Star Wars RtW on my first go).

Of course if you luck out, you might just be able to adjust the delay, one way or the other, and you're done.