I'm almost glad I never owned an NES; I find nostalgia irritating. Most old games were not that good. Even the ones that were good for their time and important in the evolution of gaming would not be good by today's standards.
You never owned an NES?? No wonder you sound so naive.
If you honestly think that games like Super Mario Bros, Super Mario 3, Duck Tales, Mega Man, River City Ransom, Double Dragon, and countless others (especially platformers) "don't hold up well", that is just retarded. Those games are as addictive, enjoyable, and instantly playable today as they were 20 years ago.
Similarly retarded is trying to compare them with games 20+ years in the future. Like was said before, that will be said about every generation of game.
Sure, there was a lot of junk, a vast quantity of of average games, and a varying degrees of true excellence. But the truly great games have already stood the test of time, and will continue to do so.