Gordon Freeman vs Link

The vote was close enough to a tie that I couldn't resist this idea.

Road Runner vs Sonic the Hedgehog 

Blue Blurs Battle

(Speedius Maximus) - The common desert road runner is a fleet-footed flightless bird with a diet that favors bird seed. Typically preyed upon by coyotes, although victories are rare and hard fought.

 (Erinaceinae Sonicus) - The uncommon blue hedgehog is a sneaker-clad, bipedal variant of the common hedgehog known for its incredible speed and agility. Typically preyed upon by robots and rotund, moustachioed scientists.