We're staying at the Westin. Can SF'istas recommend any bars, restaurants, and/or tapas places in the vicinity of Market Street that I can take my coworkers to and get them well fed and drunk?
That's literally (and I do mean literally) around the corner from my office.
Off the top of my head:
Right near the Westin is Tropisueño, which has good, not too expensive Mexican food. (Cross through the middle of your block towards 4th street, just past the Jewish Museum to Yerba Buena Lane). At the Market Street end of the same alley is Blu, more of a fancy cocktail place.
When downtown, you usually you want to seek out the tiny lanes between bigger streets. Two well-known alleys not too far away that have a few good places are Claude Lane (b/w Sutter & Bush, just west of Kearny) and Belden Place (b/w Bush & Pine, just east of Kearny).
If you like coffee, you absolutely must try Blue Bottle coffee at Mint Plaza, a lane that wraps around the Mint building at Mission and 5th--seriously, best latte ever, bar none. Also great beans to bring home. Around the corner from BB is Thermidor, another fancy cocktail place. Their pizza is delicious, among other items.
If you want to head over to Chinatown, try either Jai Yun (first choice), Brandy Ho's, or R & G Lounge.