i'd wish for ms, sony and nintendo to work together and make one console in which you can play any console game let it be Xbox, PS , or Wii/GC game

 So you want to take the entire competition part out of the market? This may sound rude, but this would be horrible long term (or even short-mid term.)

100 billion euros to buy Sega and make it come back in the console war with a new system launching 11/11/11.

Well a monopoly in the gaming industry would cause extremely high prices, little consumer choice, and mediocore quality. The reason being that consumers have no other choice. Why did Microsoft cut prices? To compete with Sony. etc.

Only one console would exist and even so, it´d be filled with great games while remaining cheap, removing the logical "but the competition" barrier.

That's not how the economy works.

Well, this genie would make it work then :P

No, you really can't argue against that. Monopolies just aren't effecient, unless they're natural monopolies, from my understanding.

"Dear little genius, I want Sony to make consoles and handhelds for ever"