I think that some people just have that look where it's serious but just so mysterious..
but everyone loves a bad boy who makes you weak at the knees :}
here's a few I can think of atm but post some which do it for you!
Kevin Flamme. oooft, that stare! so intense.
from his thread on bellazon.
eugen bauder. hot guy + leather jacket =
also from bellazon i think.
ed westwick. mmm, that smirk. his voice too. just yum.