For me, I've realized that a history together and a sense of humor are two key factors. I've also noticed I have a thing for contentious couples.
There was an incredibly sweet and personal Reddit post about how you feel about the person you love. It's worth a read. It was written in response to a woman who doesn't feel like she's attractive, and the poster explains that how no matter how she sees herself, the person who loves her will see her differently (better).
I also happen to have an undying paranoia about copyright violation, which is why each pair is represented by my very own stick figures rather than by famous images of the couples in question. Sorry if the image isn't always the best, but, hey, at least they're my very own. Also, both my scanner and my camera died, so ingenuity was used and quality was sacrificed.
Best Couples of All Time: A List by Sarah HippleOne of the most famous couples of all time. Ms. Sass and Mr. Stick-up-the-ass:
A man known for his sweaters. A woman known for her smarts:
That Blue Hair. That Yellow Skin.
Whistle, Click. Worry, worry.
The Liar and the Saint:
Last Night’s Scandal by Loretta Chase. Yep, an out and out romance novel (and not of the classic variety). Some people scorn the things, but I’m addicted to couples who’ve known each other for years, and this one was perfect for me. Not for the kiddies, though.
Mischief and Magic:
Imagination and Tuna:
Song and Dance:
Class and Cary
The Philadelphia Story, so I hope I'm not misremembering how great they were together. As for the plot: this is another pair who've known each other forever. They even went through a divorce. Watch the movie.
Sarah and Nigel (I'm reading; Nigel's on the computer:)
Let me know who your favorite couples are. I'm sure they're different from mine. Within Harry Potter alone, I had three different couples mentioned, and I only asked four people!