I've done them all (DS4 and I did the princess meal when we went without DH and DS8.) Each is nice in its own way, and has its own complications as well.
I think our all-time favorite is Goofy's Kitchen. I agree with everything Sherry has said about dinner (it's busy, crowded, loud, and characters come through one after the other) but we love it. I have two rambunctious boys, and they love the little dancing show, and they love meeting so many characters! The food is good buffet food, and you can't beat getting all those photos and autographs in one relatively short timeframe, as opposed to standing in long lines in the park.
Our Minnie and Friends experience wasn't the best, but my kids enjoyed it. DS4 loves the Pooh characters, so that was the big draw; we aren't big breakfast eaters, so we went despite that and despite the fact we were missing out on precious park time.
Unlike any other character meal we attended, Minnie and Friends had LOTS of kids wandering around, following the character from table to table. At the other meals the CMs encourage parents to keep the kids at their own table and things just seem much more orderly; I don't know why this meal is different, but it is.
I would say if you are still unsure of the kids' reaction to the characters, and if they love Pooh characters, go again to this one. If the kids might like to get in on a little dance action with the characters and you'd like to try something new, go for Goofy's. Either way, you can't go wrong.
If you're considering the others:
Lilo & Stitch is my boys' 2nd favorite character meal. Stitch is a hoot, and DS4 is in love with Minnie. We tend not to meet as many characters at this meal, though they do come around several times, and tend to stay a bit longer to visit. Stitch plays cute pranks on the kids and always gets them laughing. There's also a little "floor show", where they teach the kids to hula, and play a game of musical chairs (in this case, musical Hawaiian islands.)
Storyteller's character breakfast was much calmer and quieter than any other character meal. I worried my busy boys wouldn't enjoy it, but they toned their behavior down to the restaurant's level, and really enjoyed these characters, even though they weren't familiar with them from movies. It's a beautiful restaurant, fabulous food, and all the characters are animals, in keeping with the outdoorsy theme. They don't speak, but communicate amazingly well with gestures. We were surprised how much we enjoyed this one, and will definitely go back.
Only drawback on that one was that DS8
claimed not to be very hungry, so ordered a bowl of cereal (I think it was $8.) It was a TINY amount of cereal, so he asked for another bowl. They brought it out in one of those teeny little boxes like you buy in a variety pack at the grocery store. So we paid $16 for very little cereal, when a full breakfast was just a few dollars more. OUCH.
