No one mentioned Image Line's Harmless? I always loved the sound of minimoog leads. You have a few choices in emulation in vsti(Arturia Minimoog, Geforce Minimonsta, IK SampleMoog, and I think Image Line SAWER was supposed to be an attempt). Can't tell you which is best but heard good leads from all of them.
I agree with Deranged here. I haven't heard of Harmless but Arturia and Geforce do an excellent emulation of the Minimoog. Obi's suggestion is free so try it (no brainer). Synth1 is decent if you know how to program synths but to have not have heard of Sylenth?? cmon son .