The best burger IMO is at 4505 Meats (as others have stated). Their BBQ is also quite tasty. Be aware that they have no indoor seating though have a largish outdoor area with benches and tables. Lots of decent beer and sides here too. Taking a short walk down to Bi-Rite for ice cream (sometimes a line, sometimes not…welcome to SF) afterward is also totally worth it. Honorable burger mentions go to Monk's Kettle, NOPA, and Maven.
I haven't met a steakhouse here worth the tab yet and the few decent one's Ive gotten have been a higher end french and american places.