This deserves its own topic.
My Tofu House; awesome and amazingly cheap soon dobu. Be sure to stop by First Korean Market while you're there, great takeout and the best kimchi in the area (worth a trip fom the East Bay).
Toyose: primarily a soju bang, specialty is fried chicken wings.
Zazang: zazang myun and zam pong.
Hanuri: relatively upscale, has an extensive menu, maybe the closest thing to Ohgane in SF.
Han Il Kwan is known for barbecue but also does various stews and soups. They make great fish cake and seafood pancakes (usually thrown in free with the panchan if you order a lot).
Zazang Korean Noodle
2340 Geary Blvd, San Francisco, CA 94115
4217 Geary Blvd, San Francisco, CA 94118
My Tofu House
4627 Geary Blvd, San Francisco, CA 94118
Han IL Kwan Korean Restaurant
1802 Balboa St, San Francisco, CA 94121
3814 Noriega St, San Francisco, CA 94122
First Korean Market
4625 Geary Blvd, San Francisco, CA