Major spoilers that I'm too lazy to hide ahead!
Dramione forever! It can be so wonderfully tragic and doomed, so you weep, or improbably successful, so it sends you into fangirlish giggles! And also because Dramione isn't about what Draco is, it's about what Draco could become.
I like Dramione best when it's set during book 6, when Draco is falling apart. It's the one time when I use movie canon (the bird in the Cabinet scene), and I have Draco burying the bird, and Hermione finding him crying in the rain. She ends up either taking the Sectumsempra for Draco, or Body-Binding Harry and trying and failing to heal Draco. And of course there's the Death Eater complication. And Draco's prejudice that he has to work through, along with their old rivalry.
But Dramione with the "we loved each other since first year and had a secret relationship" plot sort of sucks.
Shakespeare would have liked Dramione!
I like Neville/Luna, simply because of cute eccentricities
Severus/Lily is tragic, doomed and lovely. I like it the way it is, and with sad little Sev watching Lily and James together scenes, but a single date, or Sev giving Lily a sweet present and telling her how he feels, is lovely too.
I don't support: Romione, because he isn't smart enough for her. Need I say more?
Harmony, because it's the same as Romione.
Luna/Rolf. Let's face it, we don't know the guy!
Drastoria. Astoria is only there for the purpose of Draco marrying somebody other than Pansy, and we don't know who she is!
Remus/Sirius. Tonks/Remus is just so perfect!
Any pairings involving: Voldemort, Pettigrew, Mad-Eye, etc.
Ohmigosh, a genuine, bona fide long post that doesn't involve fanfiction!
Soemone call the presses - or maybe Rocket. I feel like I'm impersonating her...