I'll go in order, but first gen only!\\
hitmonchan (i always pick hitmonlee)
omanyte/omastar (always pick dome fossil)
There's quite a few first generation Pokemon that I haven't trained. In Gen 1, I usually stuck to the same team pattern:
Fire, Grass, Water, Electric, Flying, Legendary
... and that Legendary was usually Articuno or Mewtwo. My Electric type was always Pikachu/Raichu. My Fire/Grass/Water was generally one of the starters (or all three, if I was playing Yellow), with Arcanine/Ninetales, Victreebel/Vileplume, and Lapras. My Flying type was either the Pidgey line or the Spearow line.
I was pretty close minded back when I was playing Gen 1.
I'm replaying the first generation games right now (starting with Yellow). I'm still using the same pattern for the first four (Electric, Grass, Fire, Water), but I'm going to use different Pokemon. Pokemon like Starmie, Hypno, Onix, and Muk. I also want to include the Eeveelutions in Red, Blue, and Green.