I must admit, I'm a bit confused by the lack of Star Wars characters. While I would personally prefer Luke or Leia, I'm sure there are plenty of people out there who would wish for Han.
Also, I would take Picard over Kirk, mainly because of what was said about Kirk: There's no one else you'd want at the helm of a battleship or destroyer. Personally, I think Picard wouldn't let it even get to that point, and on the occasions when it did, he's just as effective in combat.
Gandalf is an inspired choice. I often find myself repeating his wisdom to give me encouragement.