Experienced burrito eaters know to expect a little grime in the best chorizo, an occasional, quickly disregarded cockroach scurrying along the interior of their beloved taco truck. That's why Papalote, a neighborhood favorite tucked off the busy stretch of Valencia, is so special: It doesn't have crystal chandeliers, but compared to many other Mission District juggernauts, it's downright classy. The homemade salsa recipe is thick, smoky, and perfectly spiced, and unlike most tubs of chopped tomatoes and onions found nearby. The vegetarian set will delight in the achiote-marinated tofu (that's right, a taqueria with quality tofu) dishes, and the restaurant's meat dishes are all top-quality. Best of all, this place isn't an assembly line of standard-issue Mexican fast food. When you bite into your grilled prawn burrito with a hint of lime juice, Papalote enters a league of its own. (There's a new second location at 1777 Fulton at Masonic, 776-0106.)