I distinctly remember Donkey Kong Country as my first gaming experience. When my parents needed a babysit, they would often let me sleep at my aunts place. My older niece and nephew also lived their, but the age gap was quite big making it not ideal for us to play with toys together. One day however, my nephew had a SNES from his friend there and he was playing Donkey Kong Country on their TV. I remember being completely entranced by it and being unable to put it down (even though it was very difficult for me at the time). From then on I was always hoping that the "Gaming Machine" would be present if I stayed over, which was often the case as they figured out that this was a very easy way to keep me occupied. I later got a green Game Boy Color, and of course this was my first game for the system. I played it countless of hours, and even though I later got a Game Boy Advance SP, this game would remain in my rotation until I got a DS many years later.
I've barely played any of the later installments. I got Donkey Kong Country 2 for the Game Boy Advance when I was young, but found it to difficult and didn't really like the new protagonist as much. After my DS I became a playstation fanboy for the rest of my childhood and teens.
Now that I have bought a 3DS I've started playing Donkey Kong Country Returns. It's really nice, but I found it a bit overwhelming and haven't really touched it since.
Also a shout out to the Game Boy game called Donkey Kong, in which you actually play Mario with some incredibly varied platforming for the time. An all time classic!