There are too many good ones in LA. The issue is you have to read Chinese to find them.
There is one near Vally/San Gabriel aty Alhambra, and they serve war won ton. Har Lam Kee Restaurant at 168B E Garvey Ave, Montery Park is known for their Cantonese won ton soup. Even the chain Sam Woo BBQ or Phoenix serve decent won ton.