I think I just got done playing the perfect video game.  Raymond let me borrow The Orange Box, and I played and completed Portal, one of the games in it.  I played it in a single, 4-hour session yesterday while Eva took an unusually long nap.  If you've played Portal, then you already know how fun it is.  It's a 3D first-person puzzle solver with some fun physics and mental twisters.  Aside from that though, it is the perfect length game - at least for me.  I think if there were other games out there that were that fun and that short, I'd buy them all (assuming they were priced lower than your typical $60 XBox 360 game). 

As for the the game itself, I thought it was great that the first 19 missions in Portal were just preparation for the rest of the game! 

Just reading the line doesn't do justice without hearing it in the game, but my favorite GlaDOS quote during the game was this one:

"Didn't we have some fun though? Remember when the platform was sliding into the fire pit and I said 'Goodbye' and you were like (deep male voice) 'NO WAY!' (normal voice) and then I was all 'We pretended we were going to murder you'? That was great!"