Best: Sir Crocodile, Enel, Doflamingo
In that order.
Rereading the Baroque Works Saga, Sir Crocodile is such an overwhelming presence both physically and intellectually. He had multiple contingencies in place to reinforce his plan of taking over the nation, even if he himself were to be defeated.
Enel's just a very fun villain who's delightfully consistent in being a narcissistic menace. He's got a few really hard lines as well, "Fear is God", and in general was maybe Oda's most fucked villain until we got Imu and the Gorosei.
Doflamingo suffers from being a post timeskip villain where plot holes are more apparent, pacing is worse and the Straw Hats are background characters. Despite this he's one of Oda's best written villains, character wise, while also doing a very good job of actively antagonizing the entire cast. He legitimately cast a wider shadow over Dressrosa, chapter to chapter, than Kaido did in Onigashima. You felt Doflamingo's presence and threat whereas Oda could not convince me for a second Kaido was going to kill anyone.
Worst: Orochi, Big Mom, Katakuri
What an utter waste of a character, a position, a name. Everyone on Oro Jackson was hyped as shit when we heard the Shogun's name was Orochi. We all knew that meant someone badass, a powerful samurai for Zoro to fight. Instead we get a really lame, milquetoast antagonist who's the worst of Spandem with none of the enjoyable karma.
He overstayed his time in the manga by about 50 chapters and genuinely contributed nothing to the manga besides a cheap excuse for Kaido to be in Wano and coexisting with Oden.