Embertone Sensual Sax
Possibly the most fun you'll ever have for 20 bucks.
A couple of points:-
1. The little joke about turning the 'sex' knob up too high is a touch annoying if you use aftertouch to control modwheel (because it's not so easy to avoid going up to full CC level 127), but can be easily circumvented by inserting the JS MIDI ranger plugin (thanks Darkstar) to limit modwheel to max 124 or so (this is in Reaper, I have to admit, not Sonar). (for those wondering, it deliberately distorts the sound and glitches the UI if you set mod wheel too high. Ok, it's funny, sort of, but possibly something Embertone might wanna review because actually this is a rather beautiful instrument to play).
2. When you engage 'sensual' mode, the reverb tails are much longer and you may prefer a more seamless transition. Fortunately this has all been done intelligently via Kontakt FX sends and you can simply change the convolution reverb patches for each mode independently.
Otherwise, well, it's beautifully sampled and playable and there are also staccato patches. It also responds to an expression pedal in an absolutely natural way. I purchased Embertone's Friedlander violin the other day and I'm struck by how musical their sample libraries are - they really 'live and breathe'. Next payday I'm gonna have to seriously resist picking up their cello.