I haven't cosplayed before, but it's something I've thought about trying sometime. It's kind of hard to for to decide on what male character I like, and yet someone who isn't grossly overdone cosplay wise.
I think I would try to a Zengar Zonbolt or Souske Sagara. I think I could pull off their looks well and I don't think I've seen anyone do them before...
Of course I've also had the idea of cosplaying as my own made up character. Don't know how well that'd go over though...