In Dragon Age: Origins, Alistair takes the pedestal.
"Let's bang!" - "Um, Alistair, I'm not ready yet, and you haven't even said you loved me..." - ALISTAIR DISAPPROVES.
"Alistair, how about our future?" - "Newsflash: I'm dumping you in front of everyone!"
"Alistair, the world is about to end, I need you, a Warden, to combat the Blight..." - "Nope, nope, you spared Loghain, not caring about the Blight anymore!"
Duncan would've been proud.
In Dragon Age 2, it's definitely "Want to bang me? Get in line!" Isabela. Fenris "Thanks, we banged, now sod off for the next three years" is a close second.
And Dragon Age: Inquisition... oooh, so many possibilities! Is it Blackwall "I'm gonna abandon you naked in a barn, and hey, I totally killed those kids"? Is it Sera "If you like elven gods, I'm dumping you"? Is it Iron Bull "I know we just had BDSM sex, but LET ME EXPLAIN THE RULES NOW"? So many contenders.