Tried most of them, have a MacBook Pro dual core Leopard and Asus i7 62bit gaming notebook running Win7. Seem to be gravitating to Cyberlink Powerdirector 9 on the Win 7 as goto program. Powerdirector 64 bit is the only Windows software that runs on 64 bit and the video rendering is noticeably quicker. Some of the templates are a little cheezy but customizable. Like Sony Vegas but title generation seems a little hard to learn. Adobe, should go in recycle bin except, love how it will auto correct pictures in a batch file. Powerdirector 9 comes with royalty free music generator, smart sound and has basic library, so does Sony Vegas (different software)
iMovie is still a really easy and quick way to get a video from your clips and the new trailer templates are fun. Also found that I could get SmartSound's express free program for Mac OS and copy the Cyberdirector sound loops and load in the mac and then make custom music loops for iMovie. Tried FinalCut Express and it was a little complicated but possibilities are almost endless and like the wireframe feature. iMovie makes better slideshows, in my opinion, some throw in too much "Ken Burns" effects, IMHO.
What I usually do is make clips and output to highest h.264 movie possible and then use Quicktime v7.x with the $30 pro upgrade to render down for web, will make a SD and HD version and also phone version plus thumbnail. I started quicktime rendering for web on both the Win 64 bit gaming notebook and the MacBook Pro at about the same time and the Win 7 64bit took about half as much time. (if you want to use the QT Pro on MAc, you have to install version 7.x from the install CD)
You can get a topend Win7 i7 gaming computer and Powerdirector 9 or 10 for $1,000 less than a topend MacBook Pro, wish I had know this before I bought the Mac.