Anonymous wrote:OP, we've been to both Dutch Wonderland and Sesame Place, and I think the latter is so much better with 4 and 2 year olds. Dutch Wonderland is fine but kind of run down and anachronistic. My kids *loved* Sesame Place at those ages (and a little older)--the rides are great, they can see the characters, shows, etc. I'd recommend staying at the hotel right by the entrance (a Summerhill Suites, I think). Highly, highly recommend. We have some great memories from our visits there!
We never went to Sesame Place, but my kids, who are now teens, still talk about our family trips to Dutch Wonderland and even want to go back (and these are kids that enjoy big roller coasters and have gone to Hershey Park, King's Dominion, Busch Gardens, and Cedar Point). It may be a little run down (I didn't think so, but I haven't been in several years), but it's really set up nicely for little kids.
I'll throw out the caveat that my kids never particularly liked it when people dressed up as characters (like at Disney - they liked the princesses but not the other characters), so that wouldn't have been a draw at Sesame Place.