I have been back to Silicon valley for a few years now. I know that Triangle has closed, though. Too bad: they had a wonderful mix of electronics, mechanical, and optical.
HSC used to have much better deals in the stores than on their website. Probably still do, but find someone who's still local to confirm it.
ACE was also one of my favorite parts sources when I was living there: it was still one of those places where you could take a pile of resistors, caps and connectors to the counter and have someone say "That looks like 5 bucks worth", and make you happy because even at HSC it would be $8-10.
Surplus Computers was great for the Chinese tools and for recently-discontinued PC stuff at surplus prices.
If the electronics swap meet is anything like it was in its Foothill days, you must go if you can, and go early: when I was a regular, there were literally people shopping by flashlight as sellers were trying to set up. And you'll find stuff you can't get anywhere else on Earth: a friend of mine once bought some night-vision gear that (unbeknownst to him) was still classified. The seller was later featured in news stories about his trial: he had been dumpster-diving at some military base where damaged/decommissioned equipment was being scrapped, stealing stuff before it was sent to the crusher so the Commies couldn't copy it.