unfortunately Ulead Pictureshow 1.0 you could fit thousands and thousands (no transitions) but mp3 background music (converted to .mp2) and it was nice.
Now enter Ulead Pictureshow 2.0
Then everyone clamored for transitions so now instead of each picture being blahblah.dat 200KB or whatever it's a huge .mpg so the amount you can fit on it is limited. I had 6 slideshow VCD 2.0 I made with Pictureshow 1.0 and now that I have dvd it looks like I'm gonna be uninstalling 2.0 and reverting back to 1.0. Also someone mentioned Vegas Video 4.0 is good I haven't had a chance to check it out for slideshow yet though.