I'm recording on PC with a Delta 1010, I've been using N-Track 3.x and I think it's time to upgrade. Should I get the newest N-track, Pro Tools M-Powered, Sonar 4, whatever other options there are.
Whatever you are comfortable with and does the job. I may get flamed out the waazoo for this but IMO the sequencing program has nothing to do with the what your recording is going to sound like.
There has been ample discussion around here on this topic. Just do a search and you'll come up with a plethora of options - and some heated arguments to boot.
But, as long as I'm here - I like Sonar. You can demo Sonar and you can demo various others as well. I've used various versions of Cubase, Sonar, and even tried Tracktion before (different approach, but a decent app that really could evolve into something nice). There is another popular one too that got recommended about 2000 times +, but for the life of me I can't remember the name of it.
I kinda agree with Bigwillz....they are all just tools. Some may help with a kickin' workflow for you, others may not. There are a lot of similar features amonst them and I will say this - some do some features better (better implementation, etc.)