Well you should edit your poll dude, it still says Gaara vs. Sasuke.
Back to the thread, Bee wins this one hands down. Lightning beats earth and there is no way Gaara's sand blocks a TBB from Bee. Plus now Bee has Samehada and that is one overpowered sword, it drains chakra from things around it. If Gaara tried to use his sand directly on Bee then he would find that he couldn't control that sand anymore because the chakra he uses to control the sand would be drained, so it would just be normal sand whenever it got close to Bee.
P.S. I think Samehada is really overpowered. It drained six-tails worth of chakra from Bee in one swipe plus it can heal people and break them out of genjutsu and move on it's own (to an extent, it can bend it move slightly but it can't walk or anything xd). That is in addition to it's abilities as a normal sword. Anyone who has it can only be defeated by taijutsu after all of their chakra is gone because Samehada can just use their chakra to heal them.