[quote name='BassTractor' timestamp='1479734054' post='3178800']
Sorry, I took your initial post as a joke or ironic question, the answer to which would be "bass guitar".
Seeing you're serious, I can't really tell which of the mentioned ones is best, as I've spent only little time with each of these, BUT:
I've had great results with a synth as simple as the Korg MS-10, which has only one oscillator. This approach demanded two effect pedals, one of which I think was a chorus. The result was unbelievably close to a real bass guitar of indescript model - though of course not in every respect. I was flabbergasted though, and that was after decades of synth "programming".
The Korg MS-20 Mini, which is still available, would do the same job, and could also do a better job with its two oscillators and other stuff.
[/quote]
Agreed to that, the Korg MS series is great (although I still like the Moog filter sound better, and you can always switch off the second oscillator in a Sub Phatty)! The MS-20 mini is pretty cool but I háte those tiny keys. You could get an MS-20 kit and build one with proper keys.