I think a Sue/Cap team-up would be fun, I feel like Cap would have a lot of respect for her and they'd work together really well.
Daredevil is another one that would be interesting, he's got a long history with the FF and with his radar sense he might be one of the few people for whom the invisible part of Invisible Woman doesn't mean anything. You could get some awesome fight scenes out of Sue creating an invisible parkour course for him which he navigates with no problem while the bad guys are all just sitting around wondering how he's doing it!