To me the mark of a good writer is someone who can make the most unlikely premises work while staying true to the character. So far, precious few are able to do this.
I'm a huge, obsessive Dragon Age fan with a total fangirl crush on Duncan, the guy who recruits you for the Grey Wardens. I've even wrote semi-self insert/pure fangirling fanfiction and published it. (I have no shame; I regret nothing!). I also adore Alistair in it and can handle Zevran... *wanders off to bunk*
Ahem. I digress. Some fangirls I know go apeshit at the least littlest hint of anything remotely slash involving their favourite L.I./character; I don't. I can see Duncan/Alistair (and have read some beautifully written works) if you change their father/son relationship dynamic and accept that sexuality is subordinate to personality; Duncan/Riordan (they were best friends, after all); even Alistair/Zevran... Hell, I've seen some odd relationships which work well when you think about it (and they've been written very, very well with believable character development). The ONLY slash I could NEVER see happening would be Duncan/Loghain... *shudders*
I think people are just way too attached to their favourite pairings to appreciate that other people may have different interpretations. I respect other people's right to ship as they please... just as I reserve the right to go "WTF were you THINKING?"
As for crackiest... Twilight Sparkle/Roger.