Free Step Dodge

only the last one has a future

Wii U because of exclusives.

PS4 definitely. Wii U pales heavily in comparison. PSVITA & New 3DSXL are a bit of a coin flip based on your preferences. I think that the Vita is stronger overall, though the 3DS has slightly more games.

I agree with jjinkou2 & Force_of_Nature. Out of all of them the PS4 has a future. The 3DSXL might be a second if you play a lot of handheld games or travel a lot.