Thanks for all the suggestions!
I ended up going to only 3 arcades while I was down there (time permitted).
1. Sassony Arcade in downtown L.A.
This arcade was bigger than I was expecting. Its mostly a 90's arcade, with a bunch of street fighter 2s, Neo Geo games, gun games like Confidential Mission, House of the Dead, etc...on top of that they had a few new-console stations set up with Madden and Fifa.

Though it appears that they make their money on the pool tables, more-so than the vids.
In terms of retro, they only had 2 cabinets that were of the classic era. One was a galaga/ms.pacman reunion cabinet, which was turned up a bit too loud to comfortably play. I'm not a fan of these new cabinets, the monitors are too big for that cabinet shape, and the buttons and joys are micro-switches....the other was a hidden-away Jr. Pac-Man, which was in an area of the arcade that was hard to get to -- hard to see too!
This 'cade wasn't a total bust though, my buddy and I ended up playing a bit of those two and some Raiden in the 2 hours we were there.
btw, downtown LA is just like any other city's downtown core...dirty urine smelling streets, homeless folks, and dirty magazine stands. If you live in a city, this isn't any more "dangerous" than most city's downtown.
2.
Denjin Arcade in Simi Valley
This was surprisingly very nice arcade.
It was kept really clean, had a ton of candy cabs playing shooters, bust-a-moves, and Street Fighters. They have a separate room for the DDR type games, which is good, since those can get really annoying to listen to.
In terms of retro, unfortunately all they have is an original Pac-man cabinet, which was in much needed restoration. The cabinet wood was in nice shape, but the paint was flaked off, and the joystick leaf-switches needed some maintenance. it was still playable, but not at 100%. Other than this cabinet, there wasn't any other older game. Most of my time there was spent on repeatably owning the kids at SF4, till I was short on time and had to leave. But I really enjoyed this arcade, the atmosphere was pretty chill, it wasn't too loud in there, and it looked like it was a fairly popular hangout. I'd go back there for sure!
3. The arcade at Space Mountain - Disney Land
I was fairly disappointed with this arcade. There were a lot of newer beat games, and a few 90's games. But again, an arcade with a Galaga/Ms. Pac-man reunion cabinet, which I was surprised to see out of the 4 people in the arcade at that time, 1 person was playing this. The only other retro-like interest was their Mini-Neo Geo cabinet that had Bust-a-Move on it. That was cool to see, since I never stood next to a mini-neo-geo before...
But other than that, it was all filled with games I couldn't care less to even look at. As did a lot of people I'm assuming, since it was fairly sparse in there.
I'm going to Chicago next month, and am going to see what they have to offer in terms of classic gaming. I'm assuming (hopefully) much more than what LA can offer.
Thanks again all for the suggestions, my quest for a retro arcade experience continues...