I must have tried out nearly every extension in this category, when I finally installed Klixo Article Slideshow. It worked right out of the box and has all the configuring options I wanted. It is very easy to make it fit the layout and colors of the site.
I love the option to keep the article text formatting - this is exactly what I needed, and the result looks great.
I had a small issue with image thumbs, posted it in the klixo forum, and not only got an answer overnight, but a full-fledged update which solved the issue :-D