The Mutable Instruments Virtual Analog algorithm has some sync-sounding formants around 85%-95% of the 'Shape' dial, but a much broader range of tones could be had with a virtual synced oscillator whose pitch could be controlled over several octaves. Something like:
Control 1: Wave type
Control 2: Pitch of Slave Oscillator
Control 3: Amount of FM modulation from virtual oscillator 1-->2 or vice versa.
Alternately, one setting could be percentage of hard syncing: 50% would force the synced wave only halfway to its reset point, etc.
