The list could go on forever, regarding Pokémon that got boosts.
Evolite alone makes contenders like Onix, Rhydon, Scyther, Porygon2, Scraggy and Dusclops dealy and sturdy threats. New abilities on Pokémon like Blaziken, Seaking, Feraligatr, Sableye, and Nidoking make them much better than they were.
I could go on forever, and that's the exact reason why I won't try to give an exact answer. The best way to figure them all out is to use PokemonDB's pokédex, look up a Pokémon you're curious about, and compare them between Gen IV and V. Almost all combatants got AT LEAST a little better. Check them out!