I think Ableton Live is tha shit! I started using it a couple of months ago and the whole program was pretty much self explanatory, just got in there and started recording! Works for all kinds of music as well, I got one project that is pretty heavy industrial with much computer and synth effects, and one project that is more of the raw Black Metal kind with a nice rehearsal sound.
I like the clean gui, gives you a good overlook on all the tracks and good tools for mixing. One thing that bothers me though is that the main trax don't have a nice mute button, at least not on the version I'm working with (6) but maybe I just haven't found it yet.
Working with a Line6 Toneport GX, Alesis Control Pad, and a M-Audio keyboard, all works like small little happy clocks against Live
