Sorry, i know this is a really old thread, but it was in the official thread list. Plus, with the Virtual Console, these games could be rereleased soon!
My top games are:
1)Contra - I found this game to be extremely compelling and I always tested myself by trying to beat it as fast as i could without dieing. Also, the co-op is awesome, and it has the most memorable cheat code ever. if you dont's know it, its <font color="#000000">Up Up Down Down Left Right Left Right B A.</font color> The code gave you 30 lives!
2)Tetris - I don't know why, but tetris has always proved to e the most addicting game I've ever played. It just never gets old. Now, with the new DS version, you can play online!
3)Mike Tyson's Punch Out!! - I believe this game was the first game i ever played in which you had to figure out the opponent's weakness to beat. By that, i mean each boxer had a certain thing that they did that told you were they were going to do next. Also, doing certain things to that boxer got you a star on every hit.