Since I have eaten so much sushi over the last four years, I thought I would volunteer my reviews:
Best Quality Sushi:
This has to be Sushi Zone on Pearl Street just south of Market. This place is tiny, if you arrive after 6:30 or 7:00 you will be waiting a looonnng time. But I think it is the all around best if you are interested mainly in the sushi. Make sure to try the albacore and the Jojo special.
All around best:
Tokyo Go-Go on 16th between Valencia and Guerrero. This place has alot more than just sushi. They have a full bar and alot of specialty martinis,sakes,a nd drinks. The interior and clientele are somewhat trendy. They also offer alot of delicious non-sushi food - their calamari is the best in town, and you will also want to try the potato prawn cakes. Last, but not least, is the exceptional sushi. Excellent cuts of very fresh fish. Their maguro sashimi is consistently great. On the quality of sushi only, this would be my second choice in the city, right after Sushi Zone.
Best Budget Sushi:
Yum-Yum Fish on 21st and Irving. Home of the $2 california roll.