You might think about checking out some free ones first. One that's starting to gain some ground (and still free) is REAPER:
www.cockos.com/reaper/
It's still free till it hits v1.0, and the creator is constantly updating it. (almost every day it seems like)
Another freebie to think about would be Audacity.
Cheaper ones would include something like Sonar Home Studio (which I used for a while, and thought was very easy, and feature rich for an LE type version) or something like Cubase SE. N-track also gets a lot of play around here too. Mackie has Traktion, which is supposed to be one of the easiest to learn as well.
Most of these don't come with a great deal of good plugins, but there are many that can be had online for free (the Kjaerhus ones come to mind) that are pretty good. Basically, you should download some demos and then see what works with you best. I've always been a cakewalk guy, so to me, it's the easiest software, but it might be something different for you. Check out the demos, it's time well spent, and money not spent if you don't have to.
