I think it was Rollercoaster Tycoon, I don't know how many hours but I doubt I played any other demo for more time than RCT.

Tekken 2 ....I had just bought Playstation and had nothing else to play (I didnt pay then,my parents did),so me and my neighbour were dueling for about 2 weeks :) And, for the record ,I dont like beat em ups :P

Red Faction Guerrilla Multiplayer Demo.

The demo multiplayer was actually better then the full game multiplayer. You had less annoying weapons, backpacks and shitty maps.

Sonic Unleashed! Record time with the demo was 2.06!

Me my brother and one of his friends played the FF 7 demo over and over until it came out. Other than that I have only played a few other short demos on the PS1

Fat Princess. One of these days I intend to actually buy it.

If I assume that I played the same amount for the BC2 beta (which is a safe guess, since I played the beta throughout a period of one month during a time I wasn't busy. Versus the demo which only came out for a few weeks during my exams).

So I already got 60 hours worth of utils before the full came out.

Matt Hoffman BMX om PS2. Hours , days, weeks, months. You could only play two minutes at a time, but i had some great runs. Never did buy the game ;) Bought the soundtrack instead...

Lost Planet 2. I've played that thing at least twenty times.

@xxain: You've played the Lost Planet 2 demo for more than two hours with me alone, let alone everybody else!

I rarely play demos, so probably Pokemon Rumble at about 2 hours or so.