We've had cocky rivals, edgy rivals, friendly rivals and battle freak rivals.
However there can only be one rival that stands on top as certified BEST rival.

And that rival, is Hugh.

Hugh stands out because he's not your typical friendly rival where he's sucking your dick and telling you how great you are. He isn't this edgy/cocky guy that copes and tells you he's better than you even though you've never lost a single match to him.
Hugh is a man on a mission.
And he wants you to get stronger, not just because he believes in you but because he needs you to be stronger so can you back him up on his mission of rescuing his sweet little sisters Purrloin.
He's ecstatic whenever you beat him because he knows you're taking your training seriously and that it means he can get stronger. That maybe the two of you together can pull this off.

From the very start when you're going to receive your first Pokémon he's hype. "Finally, my best bro is getting his Pokémon. Finally we can take down Team Plasma together and rescue my sisters Purrloin."

If all your rivals found out that you had been kidnapped by the Devil himself.
Hugh would be the first, without hesitation, to storm through the gates of hell for you, to ensure you're safe.

Fuck your over abundance of friendly rivals and fuck your dream of getting another asshole rival.
Hugh is undoubtably the best rival in the series.