How about Chang's Garden in Arcadia? It's nice inside, fairly quiet, good service, lots of couples and families, and on the small side. Great spicy beef in Chinese pancake, Szechuan rice cake, and other dishes.
These things are highly sensitive to peoples' individual judgments about classy, romantic, etc., but I took a date for dinner to Din Tai Fung and had a very nice time. The pace was much slower than during the day and the food was excellent.
How about Triumphal Palace on Main or Elite Restaurant on Atlantic? Both are good, nicely decorated, not so loud. I was just at Elite Restaurant a few weeks ago and really liked the Scallops with Mango (it's mixed with egg whites, but the menu doesn't say that).