Jun Senoue used a Korg Triton (either the actual synthesizer or a VST), a Vacuum VST, and Xpand!2 to compose music for Sonic the Hedgehog 4: Episode I, Sonic the Hedgehog 4: Episode Metal, and Sonic the Hedgehog 4: Episode II, as well as Sonic Origins and Sonic Superstars (just the Vacuum VST and/or Xpand!2). Not to mention, he also used the Korg Triton VST and put it into a SoundFont for the WiiWare version of Sonic the Hedgehog 4: Episode I.
Do YOU have any of those VSTs?