San Francisco bagel shop. Located on 16th street between Valencia Street and Guerrero Street. Good New York style bagels. Get the everything bagel with cream cheese on it. It has garlic, onions, salt, sesame seeds, poppy seeds, and rye (an uncommon ingredient, nonetheless it really makes a bagel).
If you go at the right time of day, make sure to buy a bag of day-old bagels. They are usually $1.00 for about five delicious bagels, that are just as fresh the next day.
You can sit outside at Katz, and watch the junkies and bums try their luck on all the pretty Mission girls. You can also watch the Ti Couz yuppies sip their crepes while you look wistfully over at the now-closed Maya Taqueria (which used to have the best Tofu Burrito in the Mission (note, see the node for Mission Burrito).
But really you should go all the way to New York and get a bagel and a cup of coffee there. There's a good bagel shop on Church in Brooklyn, well, there's a number of good bagel shops all over Brooklyn and Manhattan. Every bagel shop will serve you hot water in a cup that reads "We Are Pleased to Serve You", and they'll bitch that you don't want sugar in it, and they'll call it coffee and charge you fifty cents for it. Still, it's worth it. Make sure to pay attention to the way they handle your order. A counter person will ask what you want, you'll tell them, and the counter person will tell the employee standing next to them what you want. The employee will then ask, for instance, if you want butter on the bagel. They won't ask you, but the counter person. Then, the counter person will ask you, you'll tell them, they'll tell the bagelmaking employee etc. etc..