yeh, some of the best vst's are free. Ive got a pretty good list for free ones.
TweakbenchLots of good effects, NES synths etc.
ymVSTa great Atari St VST plugin
Meddle & Oscilloscope synths.Less game sounding synths
E-phonicsome cool drum synth vst's here. Also snag Invader here.
Beta-bugsvarious effects
Grainzfree granular synth
Cockaigneamazing synths here. Quantum 64, Oberon etc.
Free mnimoog and arp2600 pluginsSmartelectronixall sorts of cool plugs here, check each developer. Most are effects, glitch/stutter etc.
Phadizcool phase distortion(casio cz-101) synth
These are all free, theres many more but these are the ones I tend to use most often. Have fun