For LA, I believe Verizon and Cingular are the two primary wireless carriers... so the coverage should be very similar. Given that Eghck has better luck with Verizon in the area, I'd go with his commendation.
If you click through my links above, you can see:
1. the coverage map for the LA area ( I guessed Beverly Hills, 90210 )
2. the rate plans available
a. for $70, you get 2 lines, 700 shared minutes
b. for $90, you get 2 lines, 1400 shared minutes
I started out with the $70/700 minute plan, then dropped the home phone line and changed to the $90/1400 minute plan. You can add more lines (kids, family, etc) for $9.99 each, but still sharing the same pool of minutes.
Keep in mind that cell phone carriers are like car dealers... the price quoted doesn't include taxes, fees, loss insurance, etc.