Color & Metal GenerationsTake a walk down memory lane with Red, Blue, and Yellow, the games that started it all! Then revisit the best region ever in the original Johto games, Gold, Silver, and Crystal.
Just so we know, Butterfree is actually Bug/Flying, not Bug/Poison like the others listed.
As for any of these, my choice would be Butterfree. Looks really cute, and can learn some interesting moves (particularly Confusion.)
I'm not all that fond of Beedrill - although it can learn some unique moves, I don't find it to be all that useful. Similar story for Venomoth.
My favorite would have to be Venomoth, I like its design and usability most, even though it didn't have much of significance (especially late in the game) it had Psychic, which was nice. And a better balance of stats I would say. So yeah, that one.
Venomoth because at least it's pre-evolution is half useful, the frustration i get from trying to win battles with Metapod or Kakuna scoring half points since it can't actually win a battle by itself takes forever to get to Level 18 or whatever it is for evolution.
In a quest to capture the entire first series of the trading card game then going for the 1st edition rocket series .
I caught a Caterpie in my first game and had a Butterfree, so I've always had a soft spot for it. I love all the moves Butterfree can learn and you don't tend to get Venomoth until later in the game, plus Beedrill starts off with Fury Attack which is not that useful while Butterfree gets Confusion.
Butterfree was fine up until you got to Vermillion City, but pretty useless after that due to the stronger Psychic types that became available, and Beedrill is just awful, generally. Pin Missile and Twinneedle are decent moves, but Beedrill can't land more than one hit without being KO'd.
Venomoth is one of the fastest sleepers in the 1st generation, has a wide and varied movepool and can cause all sorts of problems with its unpredictability. It's fragile, but it's not built to tank or sponge hits, it's like a Bug-type version of Electrode with less speed, very much a one-hit-and-switch Pokemon.
Venomoth is my favorite generation 1 bug type by far. It's a great Pokemon capable of sleeping other Pokemon quickly and effectively while learning a wide variety of moves. Sadly, both of its stabs for the first three generations were both physical and left the poor bug only capable of using nonstab move effectively, not that generation 1 even had wide amount of bug moves. I love it both in design and usage though.
Out of the three in the title, I would rank them, Venomoth>Beedrill>Butterfree.