well, esperanto is an obvious choice, and contrary popular belive a lot of people actually speak esperanto. Exactly how many is very difficult to say, but more than a million, that's for sure...
Haven't learned it yet though... but it's on my to-do list
I've always found dutch to be like german, with extra throat sounds added. Btw, I love german. Haven't really had a use for it in 3 years now, but i keep on speaking it just for the fun of it anyway... not that I'm good at it... it just has a nice 'sound' to it