You're a true Heathen, David.
Actually, I'm more of a Jack-ahollic than a Gyllenhaalic. I thought it was weird that I ended up liking the character Jack more than the actor himself. Anyone else have that problem of liking a character more than the actor? Don't get me wrong, I do love Jake too.
I've had that problem several times, though not with Jack/Jake. I did fall in love with Jack and will always love him. Ennis, too. But I fell in lust with Jake completely separately. And that all started actually after a few viewings of Brokeback, when I started seeing him do the talk show circuit and discovered what a lovely person he is - I had never seen him interviewed before Brokeback, so I had no idea. The first thing I saw him on was Leno, and he was an absolute DOLL. Confident without being arrogant, sharp as a tack, funny, warm, sweet, ... I could go on all day. Haven't been able to get him out of my head ever since. And don't really care to.
The characters/actors I've had that problem with, though, off the top of my head:
Will Shakespeare in Shakespeare in Love - ADORE him. Joseph Fiennes, not so much
Will Hunting in Good Will Hunting - ADORE him. Matt Damon, not so much (though I do think he's a very talented actor)
Crash Davis in Bull Durham - LOVE him. CANNOT stand Kevin Costner - I think he's The Most Boring Man in America - perhaps the world
On the flip side, I adore Ralph Fiennes the actor and the person, but I'm not wild about any of the characters he's played.