The nuke button is not a lemming, but it is very fun !
My favourite game is Lemmings 2.
I played it many nights with a friend, and we had fun resolving the puzzles...
And destroy 'em all, too : we gathered them in a single place, and clicked on the "nuke" button.
Now, i understand why we played Amiga games all night : it was 70% loading, and 30% playing (Game Over, of course
)