Apparat - The Devils Walk (haven't rolled to this, yet...just heard a song on breaking bad the TV show that led me to this album, which turns out to be IMO a good one to roll to)
Red Hot Chilli Peppers - By the Way (don't know why, maybe because people were just playing it around the time I had my best MDMA experiences

)
I'm no d&b connoisseur but older pendulum was great ('spiral' when it drops then peaks is a fond memory), Concord Dawn, and many more I forget the names of. -
http://youtu.be/Sq0Pg7fnkAg
Radiohead - Pyramid song
Pink Floyd - wish you were here
Countless other singles that I would remember if I was on MDMA now.... I'd come up with so many better tracks
Dubstep wasn't really around when I got into MDMA heavily, and haven't been able to get into it since

haven't had a good roll in yonks so perhaps it'll grow on me while under the influence.
Best mdmaemories for me would be smaller groups of around 10-15, very relaxed and plurry. The huge raves and festivals were great fun but just not quite as good in my experiences. Never been to a doof.
I agree that genres don't matter on MDMA

I can usually feel out a small group and make an epic playlist that everyone will like. Can include everything from hip hop, the beatles, 80's synth pop, rock, punk rock, orchestral, funk/soul, techno etc etc.