I like SF Supermarket almost as much as I like Diho.  It's smaller, a bit more chaotic and a little bit grubbier, but not as chaotic or grubby as 99 Ranch.  Not that chaotic and grubby are huge minuses in my opinion.  SF Supermarket has more Vietnamese items than Diho or 99 Ranch.  I have a feeling I'll end up shopping at whichever market is closest to where I plan to eat any time I'm headed to that side of town.