Seven reasons why I can't think of a nicer way to spend $100 than on a Thingamagoop mini synth from Bleep Labs:
1) There's nowhere near enough anthropomorphism in synth design
2) This movie
3) Flashing lights + weird noises = double threat
4) You can customise your own with a neat online colour-picker
5) It has a ledicle. Like a tentacle, but with a LED
6) John-Mike, who designed it, also makes other cool stuff
7) They actually explain what's going on, with an oscilloscope. (Thanks, Kim)