My wife and I moved to San Mateo last year for work. We dine out most nights, and have tried nearly every spot in the downtown area. 231 Ellsworth was not only the best place Downtown, but we think it rivals the better spots in SF, Napa, Yountville, etc. The food is excellent, the choice between bar and main menus gives a great option between casual and more formal choices, the wine list is the most thought out and interesting in the area, and their staff, from bartender to waiters/waitresses, are so knowledgable, and give a perfect amount of individual attention.
We eat here once every other week for the last year, and have had two special event dinners.