My top 3
Holds a special place to me as my very first contact with pokemon was my pal in 1st grade handing me the Rhydon card from the jungle set, shortly there after I got a pokemon poster with the first 151 from a promotion from a fish roe spread company then the show started to run on tv and I was HOOKED. Also I loved godzilla movies back then (still do) and Rhydon is like a mix of Gojira and Baragon
Literally always ends up as my dedicated flyer in any game you can get hold of it. I always tought it looked badass, also a really unique typing and great stats and, later, movepool too.
For some reason I really liked the Poliwag line, I remember beating the game with a Poliwhirl not getting how the stones were supposed to be used, and later kicking the living shit out of my friends with a Amnesia/rest/Blizzard/Surf Poliwrath. Ah, good times.
I realize this makes me look like a total nostalgiafag, which I'm totally not (altough gen 7 sucks ass) it's just logical that my first generation that I played is the dearest to me.