P.W.
I wanted to do the same thing. My husband bought the canoscan 4400F online last year for about $80. It's basic. Nothing fancy at all, but it worked! A more expensive scanner may do a better job but I wouldn't know. I was happy just to get the darn things off of my Dad's old slides. Some of them were not salvageable, but many came out great! It's hard to know whether another scanner could do any better or whether it had to do more with the old slides and photos.
I made slideshows for my kids when they graduated high school and college last year. I made slideshows with my mac and gave them to my sibs at Thanksgiving from my Dad's slides. It was a blast! I will tell you that when I updated the latest Leopard on my mac the scanner didn't work. A neighbor came over and fooled with it and got it to work again. It had something to do with the update.
GOOD LUCK!