Rayquaza has lots of power. He beat Diddy Kong and fought Fox. Snakeman is very weak. He mostly hides in his jar to keep himself safe. Not even his jar would save him from Rayquaza. Rayquaza is too strong. Rayquaza wins, but Snakeman does have his battle chips. Rayquaza wins.
DReager1.com 
megaman always wins so add his charactors to my vote list (megaman only loses when playing samus)
Megaman is nearly unbeatable. Though I do think he could take out Samus in a fight
However strong Snakeman is, he is, at the end of the day, a simple robot, whereas Rayquaza is a legendary ruler of the sky. Also, whilst epic, the picture you have put up doesn’t depict Rayquaza more some kind of Rayquaza/Deoxys fusion.
Yeah, just a fun piece of fan art. Rauquaza is powerful, but his size is his downfall. When you’re as big as he is it’s hard to fight. That’s why he got pwned by Deoxys for the most part. Also this Snakeman isn’t a robot. That’s Snake Man you’re thinking of. Snakeman is a net navi who has many powers thanks to his battle chips. It’s a close fight, but I think he’d win in the end.