my 5 cents:
for a all-in-one VSTi, try Spectrasonics Atmosphere (beware! it's a 6-cd monster). it's the best one out there (in my opinion).
capable of producing anything from lush atmospherics to harsh basses and leads.
pHATmatik Pro is a great recycle-like VSTi.
great for chopping beats.
if you're into an electronic type of sound, you might want to check Synapse's VSTis (
http://www.synapse-audio.com/).
Hydra is their biggest project up to date (besides Orion Platinum).
if you're after vst effects be sure to cop
Ultrafunk Sonitus (10 effects in one package). most of fruity-loops' plugins are based on Ultrafunk's code.
this list is just the tip of the iceberg.
I hope it'll be helpful. don't hesitate to ask more questions\consult.
best of luck!