Yangtze is an interesting restaurant offering Thai, Chinese, and Japanese cuisine. Though all of the dishes are acceptable (and there's a real sushi bar in back), they lack authenticity. The modern atmosphere can be a little cold, but the patio seating is great for people watching.
All that being said, as far as dining on the 3rd Street Promenade goes, this one is a great pick. I recommend the Yellow Curry with chicken.