Another vote for PS3. IMHO, it does a better job than some programs that costs up to $100. It is extremely intuitive and easy to use. You can add text and sound (and music). You can control transitions from shot to shot.
As said, its short coming is the lack of DVD burning capability. To counter that, I use Adobe Premiere Photo Elements (paid version). In fact, I do my slide show with PS3 and then use Adobe PE to burn DVD. They work well together.