If Sega really wants to make a comeback, I suggest making a live-action Sonic movie.  I bet most people think that's a bad idea, and that's exactly the point, because it sounds like such a bad idea that it grabs your attention.  Suddenly people are wondering how Sega will pull it off.  Who will play Sonic?  What will the plot be?  Will Sonic have a human female love interest?  Will this be the worst video game movie of all time?  But there are a few ways this initial pessimism could be turned on its head.  

One:  Big Budget.  Once people see it has a $250 million dollar budget, they'll start to wonder if this is the real deal.  Congratulations, we've just generated hype!

Two:  Big Actors.  Jack Nicholson, Leonardo Dicaprio, Miley Cyrus, and John Leguizamo as Sonic!  This I got to see.  Oh wait, who would play Dr. Robotnik?  Danny Devito?  Jonah Hill?

Three:  Big Director.  Tim Burton, which means of course Danny Elfman does the score.   

And now people wonder if this could be the first good movie based on a video game.  (There have been decent movies, but I don't know if I'd call them good)  Where Mario failed, Sonic will succeed.  Sega's back in the picture, and the icing on the cake... bring Yuji Naka back to develop a new Sonic game to coincide with the release of the movie!