I personally enjoy doing runs using Pokemon of only a single type, or monotype runs as they're often called. My last such run was in Red, with a Poison-type team of Nidoking, Gengar, Tentacruel, Weezing, Venusaur, and Beedrill. I was worried about Psychic types because of how overpowered they are in gen 1, but it actually wasn't an issue at all (mostly because Nidoking would often outspeed and one-hit KO them with Earthquake). Beedrill also came in handy because Bug attacks are super effective against Poison types in that gen.
Edited by Lugia2450, 04 February 2019 - 11:49 PM.
"Strong Pokemon. Weak Pokemon. That is only the selfish perception of people. Truly skilled trainers should try to win with their favorites." - Karen