What are the best lens choices for my Nikon D5000 for portrait photograhy?

I've been using the lens my camera came with, which is a standard 18-55mm, for about a year now. Since I'm not that experienced yet, it's done me a whole lot of good, but I'm eager to advance and get a better lens soon. So what would be the next "step up" for portrait/still life photography in my case, lens-wise?

Classic choice would be a 50mm. There's a dirt cheap f1.8 that does not autofocus on your camera and a more expensive (and nicer) f1.4 that does autofocus.

50mm is not to everyone's liking so I would advice you to try your 18-55 on 50mm to see if you like the focal length.

Next is something in the 85mm range but again, your choice in autofocus lenses is fairly limited. Nikon's 85mm f3.5 macro comes to mind.

50 1.8, unlike the above poster says, does autofocus, and is $125ish
85 1.8 $400ish
and the grand daddy of portriat lenses 80-200 2.8 VC $bajillion (okay, $1800ish)