I record all sorts for my music, piano and guitar being the main ones, but you really need a good microphone and clean signal path for it to be good for music like DnB, coz any noise you pic up is gona be loud as fuck by the time its coming out of a club sound system (you can of course do noise reduction and clean up, but that has the side effect of changing the sound you are recording)
I also love recording random things, for soundscapes and FX; although its not really necessary these days given the wealth of royalty free samples available on the net, all recorded on top quality microphones and AD's