Superman/Batman: Superman and Batman are like Captain America and Iron Man in The Avengers. They respect eachother, but their methods are very different, and they disagree with one another until they're forced to fight together and see the value in one another's efforts, building a friendship.
Superman/Wonder Woman: Mutual respect, admiration and a hint of attraction, though it doesn't go anywhere.
Batman/Wonder Woman: I like the "Trinity" concept, where, unlike Superman and Wonder Woman, who are polite to another another, Batman and Wonder Woman very loudly disagree, though they eventually come to respect one another.
Green Lantern/Flash: Friends and partners-in-crime. They're time and space, they compliment eachother, and provide comic relief.
Superman/Green Lantern: I guess there'd be a lot of respect there, especially from Hal Jordan's past, as Superman is the last son of Krypton, whose destruction is one of the Green Lantern Corps' greatest failures.
Batman/Green Lantern: "The New 52" dynamic. Riggs and Murtaugh if Riggs had a power ring and Murtaugh's parents were dead. Comic relief as well.
Wonder Woman/Green Lantern: Perhaps a reinterpretation of the Flash/Hawkgirl dynamic from "Justice League Unlimited". Jordan attempts to hit on her, she doesn't go for it, and they slowly become like brother-and-sister over the course of their association.
Superman/Flash: Respectful, I'd say. Superman was the first superhero, and Barry Allen would certainly admire that. I'd imagine Barry would view Superman in a movie as he views Jay Garrick in the comics.
Batman/Flash: Both detectives, both rational. Perhaps it'd be similar to Tony Stark and Bruce Banner in The Avengers.
Wonder Woman/Flash: Respectful. Maybe a little friendly competition.