Omg cubone for sure!
Also, I quite adore beedrill, farfetch'd, Golduck, and Sandslash. I never see enough of these!
In FR, I had Marowak as part of my main party and adored it while it was still a Cubone, even if it wasn't very strong. I'd have gotten Sandshrew if I could have, but I didn't have LG.
Poor Jynx doesn't seem to get a lot of attention in game. I had even forgotten it existed for a while. By the time I had gotten to Cinnabar Island to revive my fossils, it just wasn't worth training them up so Omanyte and Kabuto as well.
For Generation 2, you don't see much of Sunkern or Sunflora in game either due to poor stats.