Coast. LA sucks and is totally beat, avoid it aside from Venice/Malibu for sightseeing and maybe Hollywood just for shits and giggles. Downtown Pasadena rules and Long Beach can be fun (all the ______ Beach cities, really), but they're not indicative of the state IMO and tend to have at least a noticeable bit of the fake LA vibe going on (image over work ethic, if you know what I mean).
My recommendations would be:
-San Diego. Awesome night life, great beach city with a lively downtown, a craft beer mecca, and will be great weather-wise that time of year (the whole state will be, really)
-Ventura/Santa Barbara. Slower paced, smaller towns, more character/charm than LA but still pretty damn beachy and "SoCal" feeling. I live in Ventura; I'd be happy to show you guys around.
-San Luis Obispo. Way slower paced, small college town but just a really cool, relaxing place. I went to uni here, can give you a rundown of what's what.
-Monterey/Big Sur/Cambria. WAAAAY slower paced, gorgeous scenery, smaller towns with more charm and character than you'll find almost anywhere else in the country.
If you want to make it a big boozing trip, I'd advise starting in SD and working your way north on some brewery tours. Or maybe the other way around since SD has so many. the SLO area and northern Santa Barbara county will have great wineries if you're into that, but otherwise virtually every city has 2-3 microbreweries going on and we've got the regional biggies such as Firestone, Stone, Ballast Point, Lost Abbey/Port Brewing etc.
If you can find time to make it up to SF that'd be worth it, too. SF is easily the coolest city in California and is definitely towards the top of the list nationally. I rank it pretty high vs. international cities but I'm biased towards cheeky liberal hipster-centric places.
Whatever you end up doing, shoot me your itinerary on FB or via PM and I'll give you a run down; I know this state really well and would love to help you get acquainted with it.
