Yes.
For me, there hasn't even been another comic that's come close. Sure, Far Side and a few other comics made me laugh, but Calvin and Hobbes got so deep. Not even just when the philosophical sled rides and snowmen armies, but with little life lessons that even adults sometimes forget that they knew.
I dunno, it just made life SIMPLE, and awesome, like when you were a kid. I've read them for years and I still laugh at adventures that he had in his head. I mean, we ALL remember what that was like and how much fun it was! Other comics have witty punchlines that make you laugh for a few minutes, but Calvin and Hobbes is something you could read for a lifetime.
Dang...you're making me wanna go dig up my old...collection...
Ooh, and just for funsies:
http://progressiveboink.com/archive/calvinhobbes.htm