I haven't been a big fan of Ben Stiller - I think I'm just a little too old for his usual brand of humor - but I loved Night at the Museum. Ben seems to have grown into himself, a little older, a little less slapstick (although there's plenty of that in this movie), a little more settled.
The supporting cast of thousands - Owen Wilson, Robin Williams, to name a couple - are great fun.
But what makes the movie is the museum. If you've ever been to the Museum of Natural History, you'll know what I mean. A lot of the exhibits are a little (to say the least!) old-fashioned, a little out of date. But bring them to life and they're wonderful. The tyrannosaurus rex, the miniature cowboys and Romans, the monkeys and tigers and lions, the Huns - every joke is perfectly executed.
Robin Williams' Theodore Rooselvelt is great fun and not at all overplayed. Sacajewa is perfect, and Lewis and Clark are as boring as any techno-geek in today's world.
Some of the jokes are definitely for adults, but I think the kids will enjoy it as well.