Since Red and Blue, I always liked Farfetch'd. I never wanted an evo, and that one that supposedly happened is just a fanfic. If Pokemon was real, I could realistically see myself having a Farfetch'd by my side as opposed to a giant dragon or whatever crazy gojira-sized thing.
Honorable mentions: Porygon (and 2, and Z, the only post-evos I like), Muk, Dunsparce, Houou, Baltoy&Claydol, Shiftry, Gastrodon, Bronzor/Bronzong, Drapion, Rotom, Sigilyph, Garbodor, Emonga, Ferrothorn, Haxorus, Cryogonal, Trevenant
>>55003312I used this in Alola, thought it was a cool idea.