[mugen]

After using the search button extensively I still cannot make up my mind on which to get.

which one do you recommend to me?

HD600 / HD650
for
Trip hop / trance / psy trance

 

[jagorev]

650 has bigger bass, so if cost is no object I'd go with that for this kind of music.

 

[DevilDog]

Tough call. I have the 650s and love them but I've heard some 600s that sounded absolutely great.
You'll get more bass out of 650s and more bass extension. It might be too much for you, but with those styles I would think the 650s would be the better can, but only by a whisker.