Bulbasaur was my first ever Pokemon and that gives it a special place in my memory. On my first ever play through Blue I beat the first couple of gyms with it really easily while my friends struggled with their Charmanders. I kept thinking how amazing I must be at Pokemon. lol
Jigglypuff also stays in some strange, balloon shaped place in my heart because it's so freakin' cute and I remember it from the old episodes of the anime when I was watching it.