The Matrix > The Holodeck
First, let me say that this is an important topic. Public policy regarding US spying move over.
I came across a post in the science forums asking what thing from science fiction people would want to become a reality. And some people said the holodeck. That was going to be my answer when I first clicked on the thread, but seconds later I came across a better answer, the ULTIMATE answer. It's the Matrix.
But that's similar to the holodeck? Not even close. The holodeck has one SEVERE limitation. You are still bound by the limitations of your physical form. With a matrix you could have augments to your own body that made you something more than you normally are on top of all the rest that a holodeck contains. And unless the holodeck had some strange dr who time lord tech going on, you are also limited by the confines of that space. A matrix would allow an entire universe to play around in theoretically.
You want lightsabers? Matrix can give you that. Telepathy? star ships? More exotic physics than NATURE cripples us with allowing more options for transportation?
All of these things are possible with the matrix. It is the single greatest science fiction playground possible, all desires, all toys can come true there.
The matrix wins, not the holodeck. Not a single light saber, not a star ship.
If anyone can convince me why I am wrong, I will reward you with disbelief.