I fucking love Nintendo dude, I think the thing that sets apart their games from the standard modern fare is that their games and characters are always bursting with personality and maybe that's why they ultimately succeed over Sega back in the day. I mean they had Mario, Zelda, Metroid, Pokemon and other stuff and the only real character Sega had was Sonic and we all know how well he aged.
I am also a huge fan of Nintendo. The Mother series is my favourite of all time, I own almost all of their consoles, and I continuously follow all of their first party IPs for new games. Shigeru Miyamoto in particular is a genius in the game industry. His presence ties Nintendo into games from LoZ to Endless Ocean to even Cubivore. The gamecube is still my favourite console, and the ps2 is it's only competition.
Nintendo has a surprising amount of underrated games, especially in their old NES days. Clu Clu Land was a unique, if clunky game that still has charm today.
Devil World is the most unknown game they made. Probably because it was only released in Europe.
I know It's an unpopular opinion, but I actually really liked Urban Champion. Even if you don't like it, it's pretty much the grandfather of all fighting games.