Most of the choices are fairly obvious. Tali and Legion are the tech experts, they do well in the tunnels. Jack and Samara are the biotic masters, they do well in the shield role.

Team leadership also has a few choices, but they aren't as obvious. Most of your team are loners, so they don't handle groups well. So choose someone with experience leading a team (Miranda led Lazarus, Garrus led his squad on Omega, Tali led a team on Haestrom, wait, Tali doesn't work. Um, Jacob hasn't led anything in his life, but works anyway).

And don't bring anyone who's not loyal with you on the final battle. Things will go bad.

Oh, and if you send someone back with the crew, send Mordin, he's the most likely to die while you're killing the boss.