Any specific area of the west coast? That said, my experience with Ubiquity in Seattle has been pretty good. If Seattle area works for you, NetRiver is also suppose to be very good although I haven't used them.
We have worked with Netriver since 3 years+, and still happy. If you want quality, you will not be regretted with them. If you are around Seattle, drop Adam a message, I am sure he will arrange a tour for you.
You should check out Layer42 for Santa Clara and Mountain View.
In San Jose I tell people to look into the Coresite facilities.
They're all SAS-70 certified and have biometric auth with 24x7 security.
They both also have very nice lounges for when you're working on site, you won't have to sit inside the datacenter the whole time.
There are already a few good recommendations here, but I'll add a couple more to the mix. If you are looking for SoCal, I'd recommend checking with Dan at WebNX. They have a couple of different network options available and are good to work with - I'm sure you will find some great reviews on the forums about them. If you are looking for something in the Pacific NW, we recently partnered with a couple of providers up in Seattle, and both seem great so far - Isomedia and Worldlink Internet. I'd recommend checking with both of them as well. If you need contact info for any of those providers, just let me know and I'll be happy to shoot it over to you.
Rob Tyree Versaweb - DDoS Protected Cloud and Dedicated Server Hosting Fiberhub - SAS70 Type-II Colocation in Las Vegas and Seattle