LAPD North Hollywood
LAPD Van Nuys
LAPD Valley Traffic
LAFD Channel 8 for dispatch
LAFD Tac 3 for routine communications
LAFD 10 for EMS to EMS units
LAFD 5 for Brush Fires
LAFD 9 for Structure Fires
LAFD 17 (Often used for working incidents)
I'd also throw in the LAPD tac channels ( both Citywide and Valley) along with METRO/SWAT.
For LAFD I'd add Ch. 11 for command and VFIRE 21 for basic interop.
Depending on how the OP has his radio configured, I'd recommend putting all the VFIRE channels along with AIR TACTICS, NIFC and ANF in a separate bank for major incidents in the Santa Monica Mountains, along with some of the common VHF aero channels for monitoring air-air ops and new copters..