I switched to Mac a couple of months ago after being a longtime Windows person, and I couldn't be happier. I absolutely love it. I got a refurbished MacBook Pro in perfect condition for a good price from the Apple web site.
As for what programs I use - I use iTunes, iCal, Address Book, Microsoft Entourage for e-mail, MS Word, Tweetie, Safari _and_ Firefox (I can't get on to my work VPN with Safari, unfortunately, but it works with Firefox). iPhoto, iMovie, and iDVD are great. I love the Keychain program for keeping track of passwords. It took forever to transfer all of my info from my Windows password program, but now it works great and is very useful. I use Time Machine backing up to an external hard drive, and I have another external hard drive for manual backups.
I also use VMware Fusion to run Windows XP Professional. You can do this with Boot Camp for free, but if you do need any Windows programs, it is nice to have something like VMware (there is also a program called Parallels Desktop), because you can run Windows just in a separate window right on the Mac desktop without rebooting, copy things back and forth, and so on. But since I made the switch there are very few things I still use Windows for. Just a couple of quirky programs that I haven't found an easy Mac equivalent for.