Whitebox have reworked a "comes as standard" Max 4 Live Instrument, Laverne, which is described by the developer as a "working class subtractive synth", by giving the machine's dull GUI a wash and brush-up.
This synth has two oscillators, 8 voice polyphony, and a VCF plus VCF Envelope. The User interface is now clearly laid out.
It requires Ableton Live 8 and the Max4Live plugin, both available on 30 day free trial from these links.
Price: Free.