I thought Applebees was arguably the worst chain, but Rain Forest Cafe definitely "wins" in terms of food. The ambience is fine for kids, but I would not conscionably allow them to eat there.
I've had the misfortune to eat a RFC twice and both times the meals of the restaurant came to us as if from a rain forest - read: they were wet.
-- Wet meatloaf
-- Wet Thai salad
Gooey and nasty with little redeaming feature. The food was either too salty - probably to make up for the wetness - or too gooey, because they had a large amount of sauce in the back that was probably meant to mask the absolute insipid tasteless food that was being presented.
The other insult is that the food is not cheap. I would much rather eat at Applebees or for that matter, any roadside diner - especially if someone at the diner could dress up in an ape suit and there was audio tracks of a rain forest in the background. Then my kids would appreciate it, too.
Pros: sounds of the rain forest
Cons: insipid food