Would be great if you could get someone like Illitheas to make a course. I love the fusing of Trance and Orchestral.
The harder side of trance would be good: Sam Jones, Shugz, Renegade System, Billy Gillies Will Atkinson for example.
Hardstyle/Rawstyle/Hardcore (esp making your own kicks!)
And a hip hop tutorial would be kind of interesting.