Oscar and I ate some twins this morning. 2 everything bagels, toasted and slathered with pesto garlic cream cheese. Head towards the giant bagel when you want the real deal (although admittedly Katz Bagels may not please all NYC natives). Their bagels are remarkably better than any air puff you'll get at Noah's.
Oscar stayed quiet as we ate, while I watched a bike messenger, young lesbian couple, and 2 older gents (1 with a very pimpin' Run DMC huge gold chain) order, pay, and move on. There are also large photos of locals to look at, taken by Mr. Katz himself (companion book available but the store's pics fulfill that urge). The service is friendly and prompt, and I like to practice my kitchen Spanish if it's not too busy.
Katz Bagels has good, strong coffee that isn't too bitter. Espresso drinks are available, along with bagel sandwiches. Be warned, the pesto garlic stays on your breath all day, but is worth it. Other cream cheese options include: plain, lowfat, sundried tomato, lox, and dill (with cucumber chunks that stay firm). Using the restroom (ask first, or you'll get stares from the staff) in back offers a view into the bagel making operation.
Katz Bagels: 3147 16th Street, near Guerrero. 415.552.9122.