You might want to consider going a little past the city limits. I like St. Michael's Alley in Palo Alto for brunch.
I would definitely not go to Buck's for any food these days. The last two or three times I have been forced to eat there it's been terrible. They survive on location and big portions.
Are you looking for a buffet, or just a place that makes good eggs and where you can order champagne? How far are you willing to travel?
Don't know how good it is, but Bay 223 serves a Sunday buffet brunch
Brunch menu (pdf)
Buck's also has brunch
Alana's might be another option