Thái So'n is by far the best of the bunch in this Vietnamese quarter of Chinatown. It's neither massive nor fancy, but it's bright, clean, and perpetually in business. One peek at the specials on the walls (maybe golden-fried squid strewn with sea salt) will have you begging for a seat in the crammed room. Speedy servers scoot between groups of City Hall suits and Asian locals as they order the likes of cha gio, pork spring rolls with nưac cham; or goi cuon, fantastic summer rolls filled with poached shrimp and vermicelli. Naturally, pho choices are abundant, but the real star of the show is pho tai —where raw beef shavings are cooked to tender perfection when combined with a scalding hot, savory broth replete with herbs, sprouts, and chewy noodles.