Ten Year Reunion:
Everyone still seems fairly similar to the way you remembered them. The nerds are starting to show signs of wealth. The jocks are beginning to get fat. The hell-raisers are trying to corral their rambunctious brats. But the girls still look real good.
Twenty Year Reunion:
The nerds are just outrageously wealthy now. It like in Romy and Michele where they're flying in with their own private helicopters, just to show off. The jocks have already had their first heart attack. The hell-raisers are back on the bottle and perhaps the blow and are not looking very well at all. And even the girls (except for those two or three that you just knew would never go south) are looking really weird.
Thirty Year Reunion:
Didn't even consider attending.