Hey,
Everyone here knows how much I love Reaktor: with enough brains you could program your own Reason or Fruity Loops. Is it good for 'west coast' tracks? It's good for ANY tracks, but it won't do the work for you.
Additive, subtractive, FM, AM, PCM, granular, formant synthesis; runs as a standalone or plugin; compatible with all the major sequencers (even PT now, which is sort of strange), and you can find a buttload of synths on the net for free download or purchase.
This is the only softsynth I run on my computer because it KICKS SO MUCH ASS.
Take care,
Nick