1. Super Mario Bros. 3 - First videogame I ever played. 8 worlds full of action. Special items and secrets. Nearly perfect platformer.
2. The Legend of Zelda: Ocarina of Time
3. Super Mario 64
4. Donkey Kong 64
5. Paper Mario
It's impossible to choose top 5 nintendo games. There are many great games. Mario Kart 64, The Legend of Zelda (+MM, LTTP, WW) , Super Smash Bros. (+Melee), Banjo-Kazooie & Tooie, Jet Force Gemini, Metroid (Prime, Prime 2, Super) for example. I could continue the list forever.
(Sorry my bad english)