Charmander/Treecko. I like Bulba/Ivysaur more than Charmander/Meleon, but I always found Charizard to be the coolest. Treecko... I fell in love with that Pokemon when I first saw it, and when it evolved into Grovyle I was so happy... he was so cool.
I never had Ruby, my sister did; she would let me reset all the time as long as I didn't save, but as a kid I had so much fun with it. So one day I had extra time with it and got to evolve Treecko and boy was I happy. I kept asking to save, but I couldn't. Eventually I got it, though: one Christmas I was doing the same thing again while my sister opened up a present. This present was Sapphire version. As soon as I realized, I pressed start, save, and A.... She was mad at me, but I finally got Ruby. :') Good times.