Justice aviation at Santa Monica. Free parking, beach is 10 mins away and they have some nice aircraft,(and some quite cheap ones too!)
V UK friendly, they put up with me for years!
Do a check out flight to Catalina island, also gets you to fly over LAX midfield....try doing that at LHR! Another good one is to ask for a flight over long beach/QE2 then low level up the LA "river"/Dodger Stadium/Hollywood sign/Downtown/Sunset strip. Takes about 1 hr 20 chock to chock....or
about 70 quid including instructor for the checkout!
Have fun.