p.o.d. Planet of Death : Sci-Fi racer with outstanding graphics (for its time), very creative futuristic tracks, pushing soundtrack, nice handling and even a plausible storyline. Maybe some one remember it as "that racing game that came with my new Pentium 2 MMX computer". A pain in the ass to get it working on XP systems, but possible.
Alien Shooter 2 : Blow shit up as epic and gory as possible. German made low budget isometric sci-fi shooting rpg whatever game with dated graphics but funny as hell. Download the demo if you like [http://www.sigma-team.net/games/action/alien-shooter-2.html]
Super Mario Bros.2 : this game gets so much hate

and I am sure it is only its "they lied to us !!" backstory. Beeing a child, I didnt knew that fact and I could enjoy it. Slap me, hate me, bite me, bash me but I prefered it over SMB1.
Star Tropics : some reviewers this day like it to give this game the "its a Zelda rip-off" fuck you, but they oversee that this game is still a great adventure on the NES and the only game I know today that broke the third wall and offered a puzzle that forced you in real life to put a letter, that came with the game´s box, into water to let it show you a secret code required to go on in the game.