The documentaries the other day got me thinking about the ones I enjoyed as a kid, so sure enough those were on Youtube as well. In particular this claymation segments from "Dinosaurs! - A Fun-Filled Trip Back in Time" is one that I always liked. If you're looking for some serious groans (and a song), the first part is also worth a look.

The PBS Dinosaur documentary is also pretty incredible! I remember watching this one as a kid, and the animated segments, interspersed throughout, really gave me the creeps. Even looking at it now it's still very impressive and convincing, I think moreso than most CG efforts these days.