I always wanted to catch them all! But I had Pokémon Crystal, and though I got some help from someone with Silver, there were still some Pokémon I couldn't get. Even if I had known someone with Gold, I never would have been able to get a Celebi.
I helped my friend with Pokémon Blue to fill her entire pokédex, though! We were so excited to find out what incredible prize we would earn for doing this, you can only imagine how disappointed we were when we found out that all we got was a stupid diploma.
B/W? Never played.