Great film. Much more complex (and at times dark) story line. Although I'm sure kids would love seeing Buzz, Woody and all their favorites again, adults will appreciate the tale of loyalty, struggle, anger and acceptance. The allusion to WWII concentration camps is at once unsettling and thought provoking.
In addition, there are some great one liners, and some fun new characters. Great way to end the series!
If you are looking for a mostly mindless action-packed violence thrill, it's great. If you are looking for plot subtlety, not for you. It's basically a Punisher comic book brought to life, without any major additions or subtractions.