Well... I would want Deidara to win cause I like him so much, but in reality (or at least anime reality), it would be Tobi who wins. I mean, he's Madara Uchiha, an all-powerful shinobi. I doubt Deidara could beat him atau even land a hit on him.
(Read comic from right to left) Deidara: Uwaa! Doing that sealing jutsu really tired me out! I'm going to go get some artistic sleep, hm! And anda better not do anything stupid, mm! Tobi: Ha! Ha! Wakarimashita (I understand in japanese)! Tobi is always a good boy!
Deidara: Tobi Kisama (a vulgar form of "you" in japanese), mm!! Just how do anda explain this, mm?
Tobi: It's art! Senpai didn't anda always want me to improve in art, huh? Well, I did improve! Tobi is such a good boy!
Awwww, give Deidera a chance people! After all, Deidera is a bad boy like he's supposed to be! Unlike Tobi, he's a good boy! I swear! Where do they find recruits like Tobi uh!