If it's gotta be Windows, Adobe for sure. It will be the closest thing to Final Cut that you'll be able to get.
I concur. Adobe Premiere Pro 2.0 is a
phenomenal Windows-based editing suite, and its integration with the other components of the Creative Suite is very nice. It also boasts native export to Flash video, which is very convenient.
Otherwise, Sony Vegas and Avid Express (the full Avid suite would be overkill for you) are very solid, as well. Ultimately, when it comes to video editors, once you hit a certain price/feature point (so, the level of Vegas / Premiere Pro / Avid Express / Final Cut), it ultimately boils down to user preference. Premiere has a slightly less intuitive interface, but its titling program, derived from Photoshop's text engine, kicks the crap out of Final Cut's horribly clunky titles; Vegas has
excellent audio tools (because it was originally developed as an audio editor, with the video component built later) but it lags behind Final Cut and Premiere in smoothness and quality of video transitions.
At the end of the day, though, anything that I can do in Final Cut Studio on my MacBook Pro, I can just as easily turn around and do on Adobe Premiere Pro on my Windows XP machine. Ultimately, when a video is being edited, it's not the program that matters (with some exceptions at the very low end*) -- it's the skill and the editing sensibilities of the person using the mouse and keyboard.
* If a program has Ulead or Pinnacle on the box, avoid it like the plague, as it's nothing but utter trash.