I've run across plenty of Pokeymans at Yerba Buena Gardens, which is just across the street from the W. Also you're right next to the SF Museum of Modern Art, which is frankly fantastic; it's just reopened after a huge three-year renovation, and I think it's the equal of the NYC MoMA.
If you're looking for good lunch places, hop on Muni to Embarcadero station and go to the Ferry Building; there's a ton of brilliant food places there, and it's extremely popular with the finance crowd that works around there.
For dinner, it really depends what cuisines you like. Hop on Yelp and see what gets high ratings around where you are (though if you see Hakkasan on the list near your hotel, probably skip it and look further out - it's not bad, but it's horrifically expensive and a bit overrated really).