URS Compression and EQ plugs.
Now I have tasted these beauties, I can`t live without them.
Waves is all but in the bin if it weren`t for the L3.

Synapse Audio Hydra. The best bass synth bar none. It goes lower than all other vst`s and holds it together right down to silly low notes C2-C1, you can feel the air physically moving with this baby. Plus the low pass on it is pure evil.

Sonalksis Stereo Compressor.
It`s just amazing.

Voxengo Marquis.
Again, amazing, fantastic response, and really silky too.

FM7/FM8
Gotta love FM synthesis, and now with morphing capabilities it`s a wet dream.

Pro 53.
Just too damn versatile to lose it.