Finally beat Red with Monotype Bug! Very surprised by where I had trouble, which was really only Lorelei, it was terrible! I had absolutely zero trouble from any other boss, but jeez, her Ice moves are terrible. Bug was really useful first gen, strong against so much.
MVP - Gambit
Slash - Swords Dance
Leer - Rage
For the time it took to save up the money for Gambit, he was worth it. Gambit's best feature was the absolute Speed hacks he got for Criticals. Since they were based on Speed instead of Luck, every Slash from Gambit was a Critical, making him a devastating force. Gambit ended at the highest level, and had two stats over 140, acing through Pokemon that should kill him normally. Slash was clearly the main move, and pretty much the only move I ever used. Swords Dance, Leer, and Rage just kind of happened, but never actually helped because of how the Criticals worked first gen. If Criticals worked this way in other games, I would use a Scyther every time.
LVP - Sgt. Sting
Poison Sting - Twineedle
Pin Missile - Skull Bash
I expected Sgt. Sting to become obsolete, but he really served his use for the first 6 gyms much better than I expected he would. With Bug type's incredible power in the first generation, he was the wild card that took down Poison, Psychic, and Ghost types with ease. However, his low stats really shined once we got to the Elite Four, and I had counted on him to take out Agatha. However, he didn't do really anything for the last stretch of the game, and unfortunately got placed as LVP because of it. Poison Sting was never really used, and was simply a relic of his old Weedle days. Twineedle was Sgt. Sting's best attack, as it was both powerful, hit twice, and could poison. Because of this, Twineedle was Sgt. Sting's main attack, and was quite useful while Sgt. Sting was helpful. Pin Missile was Sgt. Sting's other Bug type move, and was used on bulkier Pokemon with more health, since it had the chance to hit 5 times. Skull Bash was very useful, as it allowed me to hit targets that Poison Sting and the Bug moves didn't do well with. Sgt. Sting was extremely useful as an early Pokemon, but just became unusable as the late part of the game progressed. I could see using him again, but not as a permanent member of my team.
Margarine
Solarbeam - Psychic
Toxic - Sleep Powder
Margarine was a useful Pokemon on my team, especially as it was my main Special attacking force. Both of Margarine's offensive moves, Psychic and Solarbeam, provided excellent coverage from Poison and Rock types, both being boosted by an impressive Special stat. In addition, Toxic and Sleep Powder saw their use too, especially in the Elite Four, making it actually possible to beat some of the tougher Pokemon. Butterfree was very good in this generation, however most of her Special stat went into Special Defense, not Attack, making Butterfree a much less useful Pokemon. Playing Red, I would love to use her again.
Slash - Mega Drain
Spore - Dig
Fun Guy was a very good balanced attacker on my team, having high Attack and Special, complementing Slash and Mega Drain nicely. Slash was my basic move, since it had the highest PP, but whenever I had type advantage, I would go for Dig on Fire types and Mega Drain on Rock and Water types. Spore was a very tactical move, and actually made it possible to defeat Lorelei's absurd Pokemon. Even with 3 quad weaknesses, Fun Guy made an excellent addition to the team, and I would gladly use him again in a later game.