For one take on 3D Snakes and Ladders, there is Get Jack Back! from Fiesta Crafts.

In this game, you stick your magnetized pieces onto the side of the game board as you climb up, and then back down. So ladders and snakes reverse their usefulness in the second half of the game.

Another take is 3D Snakes and Ladders from Perner Productions.

In this game, there are five boards and the player pieces are marbles. Land on a snake and you roll down the boards.