Eyeliner definitely suits guys. I draw the line at lip gloss, though, but that's cos I don't like it myself.
Darkness (e.g. chest hair, thick eyebrows) is a sign of testosterone and masculinity and really gets the girls going, so black eyeliner is v. hot on a hot dude.
Not Dale or Stu though - they were ugly on the inside and looked like muppets. Dale looked like a skinny, drooling version of Randy from 'My name is Earl', ha ha.