I think a good way of seeing this, is by looking at the 8th gen console that is winning right now. PS4 is just picking up the footsteps left by PS3 and in the end of the race, PS3 won for both relevance/staying power & innovation. The faulty thing about PS3 was the price but everyone wanted one BUT not just anyone could afford one and migrated to the competition. And then of course the competition defended themselves how the could: payed online service & motion controls gimmick becoming mainstream for the 1st time in history (not for a long time however). Difference is, who managed to stay relevant till this day and probably until 2016? PS3 did this, and this matters most.

connecting 2 devices with a cable doesnt make it remote play. It was a clever 2nd screen / alternative controller solution, but thats all it was.

Nope.
There was an adapter released for the Gameboy advance that connected to mobile phones for remote play.

Do you know what it was called? Im not aware of it and cant find it on google using generic terms.

edit:

if you are talking about this, it just a network adapter.

http://bulbapedia.bulbagarden.net/wiki/Mobile_Adapter_GB

Was thinking the exact same thing

@OP  Microsoft for Online Gaming and achievements which effects the majority of games still today. Also puhing for an all in one entertainment box and Kinect with voice control though credit also should be given to nintendo for that which takes me to number 2

Nintendo with motion controls

Sony has blu-ray, maybe not be as innovative as the others but it is something that plays a role into the current gen.

I am shocked that the voters here got it right.

1 true but us that really enough to be considered relevant? Taking into account also that it's hardly used meaningfully in most of the games available?

2  cameras were used for gaming long before the wii on pc Sega consoles and eventually even by Sony with the eyetoy

3 I can't really consider it as such since it isn't standing the test of time