Smallville, The Pairing Capital Of The World! ;)
I love Clex first and foremost, because the chemistry between them (and TW and MR) just jumped out at you from the screen, but I've grown fond of other pairings, too. For Clark, I can see him with Ollie. I can see Chloe/Lana, Lois/Lana, and Lois/Kara. I enjoyed the canon pairing of Ollie/Lois, and can buy Ollie/Chloe. I thought there was real chemistry between Ollie and Zatanna in her very first episode (Hex). I can see Lois/Chloe (yes, they're cousins, but I've written brother/brother, so cousin/cousin doesn't scare me).
Tess? Jeez Louise, try every woman she has a scene with! Lois, Lana, Chloe, Kara...heck, she'd probably sizzle with Dinah if we got to see Black Canary for more than just a few episodes here and there.
Yeah, I don't like Clana, but Clois is fine with me. :) I think Lana has far better chemistry with women than men, just like Tess (though Tess/Emil I can buy).
This does sound like an orgy, doesn't it? LOL! But it's great fun to see what comes up. And think of how much fun it would be to add Bruce from Batman Begins or comicsverse and Diana from comicsverse (and maybe her new TV show this fall)!
Smallville often got it wrong, but just as often got it right! ;)