The 3DS versions are amazing remakes of perfect N64 titles! I would say if you value Nostalgia and playing with the original controller, go with the N64 versions. However, currently it's cheaper to get the remakes, which have better graphics, controls, and portability.

I was the first person to review this game on eshop lol. It's a fantastic game and an amazing improvement on the flawed, but excellent original. I highly recommend this game! I can't begin to tell you how amazing it is to play dementium in 3d!