The challenge on Super Mario Kart is great as well. 50cc Mushroom Cup you can win with your eyes closed. 150cc Special Cup is still very hard to do. Perfectly balanced.
Like you, I love modern games, I have a 360 Elite, I have Halo3, GTAIV, BioShock, all the usual suspects, but games were better during the 16bit golden age. Maybe its rose tinted specs, but almost all of the true classics are pre 7th generation.
No modern fighting game is as good as Street Fighter II Turbo.
No 2D platformer is as good as Super Mario World.
No racing game as much fun as Super Mario Kart.
No adventure game as much fun or as magical as Legend of Zelda: Adventures of Link.
No 3D platformer as good as Mario 64... apart from Mario Galaxy.
I also started gaming early - ZX Spectrum 48k.
Plenty of classics from that era as well, Jet Set Willy, Manic Miner, Dizzy, etc, but Nintendo in the 90s were just churning out all time classics all over the place.
As they were in the 80s, with their 8bit classics. The sacred cow that is Super Mario Bros, and Super Mario Bros 3 which just blew everything else out of the water.
And now, well into the 21st century, they are still coming up with Mario games that are a cut above everything else, and the Wii is outselling both the 360 and the PS3.
Got to take your hat off to them really.