If you liked Toy Stories 1 & 2, then this is a MUST see. If you somehow have not seen the previous Toy Story movies, no worries. The story line here is not dependent on the previous two but it helps.
Caution. While I have seen some reviews play down 1 particular scene too intense for tiny tots, in my opinion, scenes of eminent death of a child's toy will affect kids. Share with your kids and talk to them about it. It shouldn't lead to nightmares but a little comfort goes a long way.
Other than the 1 scene, the movie is truly a great one to see. Our audience applauded twice DURING the movie, not even at the end. It's that good.