PikaChoose
I choose you!
I’ve been playing around with the lovely jQuery image carousel plugin PikaChoose and it’s been quite friendly to me. The best thing about it is that it handles all the list-building, which makes it quite easy to integrate into an Ajax-drive project while also remaining very styleable. It also integrates with FancyBox, giving you some very nice possibilities with an image library beyond a mere carousel.
There may be more robust slideshow plugins out there, but PikaChoose is very easy to set up and looks great.