I would like to see those two in an intercompany crossover where they don't fight based on a misunderstanding or mind control, but instead are friendly and help each other beat whatever.
I'd also love to see PG paired with Thor....I think he'd like her...the Hulk, (because of an old DCU message board joke where a poster named Hulk or something who obsessed on "white underwear girl", Power Girl).
And Captain America---I think she'd admire him.
Who else would you like to see her paired with from Marvel....or indeed any other property. Judge Dredd and Power Girl?