GC: Froome. Sky is just too strong and Froome looked strong in Romandie and the Dauphine (at least before he crashed). Contador & Tinkoff will make it interesting but Porte and Kiryienka will crush the group in week 3, as usual. I predict Nibali is going to be a hell of a lot stronger than he's shown so far this year but will crack at least once.
Green: Kittel. He looked dominant before he got sick in the Giro and Giant's train is likely the strongest. Cav is missing some key members and Sagan doesn't really have a train. Put Sagan on a team with a reasonable train and he'd wipe the floor.
KOM: I have no idea, perhaps Mollema. He looked very good in Suisse and is due for a big performance in a Grand Tour.
White: Bardet. Very strong spring and AG2R looks tough this year. I'm really enjoying the rebirth of French cycling recently, they're pretty much the only teams I trust (outside of Garmin).

Dark horse: Talansky. The Dauphine wasn't a fluke, the guy's a genuine threat. He can climb and TT with the best of them and Garmin is sending a strong team. Also, the Garmin DSs are smart and have the ability to cause chaos. I wouldn't be surprised to see Talansky podium.

Overall, I think we're in for the best Tour in years. Certainly better than the last two Sky snore-fests.