My guy crushes, much like my girl crushes are based more on characteristics and talents than looks...for the most part. Although I think all these men are beautiful in their own way...just not perhaps classically beautiful. But all of these men, on top of said admirable characteristics and talents, have made me, shall I say, weak in the knickers from time to time...
Colin Firth...well, swoon.
Paul Giamatti...has chosen his roles well and is in some of my favorite movies of the last ten years...plus he's adorable.
Jeff Bridges...I will always love him for Lebowski. Always.
Dexter Gordon...had a mad crush on him about 20 years ago.
Lou Reed...Velvet Underground followed by 30+ years of quietly making one great album after another. Plus he married Laurie Anderson, pfft. Yum.
Leonard Cohen...when he sings
'give me crack and anal sex, take the only tree that's left and stuff it up the hole in your culture'...well, come on, how hot is that
Don Cheadle...just look at him. My image of him will always be tied to his role in Boogie Nights, though. I loved him so much in that movie.
James Mercer...wrote several of my favorite songs from the last ten years. No small feat.
Bob Dylan...sure, he's looked better, but he's a genius. A genius I'd like to fuck.

(well, if I weren't already fucking someone else, heh)
Bill Murray...grawr
Gary Oldman...a legendary actor even if he did fall off the credibility truck quite a few years ago.
Joseph Cotten...kind of a pivotal guy crush...one of my earliest that wasn't someone a) living and b) in any music magazines, lol.
There are more, but that's all I can think of right now.