I'd have to say this is one of the best animated films I've ever seen. I liked it the first time but really appreciated it on the second viewing, just a few weeks ago. I can see why sequel is doing such great business at the box office. Apparently, a lot of people liked this movie.
A gorgeous color palette (man, this looks good) and a lot of good adult (but clean) humor make this a big winner. The opening 3-4-minute scene with "Scat," is excellent as are subsequent interludes with him. "Sid" the sloth (voiced by John Leguizano), however, provides the main humor in the movie. He usually has something funny to say throughout the movie.
Ray Romano is the voice of the mammoth, the big character of the film, literally, while Denis Leary is the ferocious bad-guy-turned-good sabertooth tiger
This isn't just humor and pretty colors but a nice, sentimental story of how a little baby softens up a couple of tough characters. This isn't interrupted with a lot of songs, either: one only brief one and there is nothing offensive, language-wise.
If more animated movies were this good, I'd own more.