I'm 21 and, despite it being past its time, my first console was the NES. It was handed down to me from my mom and I really enjoyed Contra, Super Mario Bros. and Kid Icarus the most despite the fact that I never once beat them at that young age. Other games I played I have no memory of what they are. I recall when I played with my grampa, may he rest in peace, with him being Luigi and I "taught" him how to play.
In fact, my mom said she beat The Legend of Zelda while she was pregnant with me. XD
I may have been born at the end of the NES's life, but it was my first console and the nostalgia is just as valid.