Smitty's on Lake (626) 792 - 9999
110 South Lake Avenue
Arroyo Chop House (626) 577 - 7463
536 South Arroyo Parkway
Parkway Grill (626) 795 - 1001
510 South Arroyo Parkway
They are all owned by Smith Brothers http://www.smithbrothersrestaurants.com/
Also, would consider Spaghettini's in Seal Beach (one block from exit off I-405) though it can get quite expensive.
Their menu is not just Italian, it is a variety for many palates and needs from pasta, to fish to steak. And, don't let the "jazz club" mislead you to think it is anything but high quality. It can get lively in the bar side, but noice level is properly shielded from the restaurant. Some fun!
re: Oh Robin
My father turned 80 a couple of years ago and we (his family!) had a lovely dinner in a private room for about the same number of people that you are having... It was at Patina's in/next to the Disney Hall. Not cheap but wonderfully memorable and delicious, special, great -- as an 80th birthday should be.