Sony Vegas is not .. even.. close.. to Final Cut. Sorry. Vegas is for home editing. and that's it. Nobody would use Vegas for a real workflow.
Adobe Premiere is about as good as Final Cut but again it depends on what you are doing. It won't be used for a heavy workflow or heavy media management, but if you're just cutting and chopping up some home movies it's fine. (Yes it is heavier than that.. so don't get pissy all you adobe fanboys)
Final Cut is great..but I hate it's media management.
I'm on Media Composer from Avid.. but.. it's a bit pricey. It will work on XP just fine. It has a very steep learning curve however. So, since I don't know what you're doing with the NLE I don't know how to really direct you in your purchase.
Another great option is Edius Pro. Edius software doesn't need any hardware add-ons like FCP and Avid generally do and for the $1,000 program..you get Real Time Render. That's a huge bargain for $1,000. It's interface is fairly clean and easy so you shouldn't have any problems using it.
So really.. what are you going to be using an NLE for? Hell you may even just be able to get by with After Effects. The right NLE is real dependent on work flow and media management.
I love Avid but it's not for the faint of heart.. and I like Final Cut .. but for me it's like this Avid>DPS Velocity>FCP>Edius>Premiere>>>>>Vegas
and just an FYI, Pinnacle was bought out by Avid a few years back.
