My favorite is
www.skype.com
I hate flash but you have to admit these others are pretty cool.
I think something big will change with html 5 and we will see a new norm. I should say I really like the skype website, simple wins big points, no auto moving parts I have a click and want to use it.
One thing I hate that more sites are doing is a bar like a addon for your browser. This really pisses me off lol