I'm on my third pair of Uggs, and I'm addicted. I can usually get two snow belt winters out of a pair before I have to toss them (and this is wearing them pretty much every day from October to March). DEFINITLY waterproof whichever ones you get. I've had the traditional camel, the chocolate, and right now I have the chestnut. The chocolate ones weren't my favorite because they showed salt stains really bad. I vote grey personally- I've been eying them myself!
I'm a size 8 or 8.5. I've found I can wear the kids size 6 and save the $20 or $30 difference in price from kids and adults. There may not be as many options as the adults but the standard colors and options are available in kids.
I have the chocolate "bomber" classic tall ones. I get a lot of compliments on them because they look more like typical leather boots than the suede Uggs do, which is why I got them. I really don't care for any of the other Ugg styles though, and I definitely never wear them with dresses, skirts, shorts, or (the worst) athletic shorts.