Shiver Man and Terror Inc - Two supernatural bounty hunters on a case where the whole world is in jeopardy.
Invincible and Spider-Man - I'd like to see Invincible in the Marvel Universe again.
Grifter and Agency X - Would Deadpool feel threatened by an equally skilled and more sane hitman working by his side?
Crime Syndicate of Amerika and The Authority - obvious reasons
The Authoriteens and The Authority - I really want to see how the kids would react to their adult selves (and vice versa).