Voxengo's Boogex gets my vote as easily the best-sounding and most usable guitar amp, at any price, that we've seen to date. To non technically-minded guitar players like myself the interface may be a bit off-putting - after all it IS more complex than my old Super Reverb but Aleksey at Voxengo really does know what he's doing and every knob is there for a good reason. The Emphasis and Cut filters alone give endless sonically pleasing possibilities once you've got the hang of using them, so it really is worth taking time out to fully understand and master this superb plugin - your patience will be rewarded. Why does it sound so good? As somebody said in one of these testimonials: "Aleksey has better ears than the rest" - it's as simple as that.
Here's an interesting forum thread that gives an insight into Aleksey's development of Boogex: http://www.kvraudio.com/forum/viewtopic.php?p=1231892