Does Any Other Site Have Quick Looks?

I'm not sure, but my instinct says, "No." One of the reasons many of us post on Giant Bomb*.

As far as I'm aware, no, and that's just another reason of why Giant Bomb is so good.  :)

Well youtube and something awful do let'splays which are basically endurance runs. And people like Angry Video Game Nerd go back and take looks at classic games.

Well, 1up has "Gamer Nights". Besides standard preview videos, no, no one else does :D

Yeah and they are usually about 5 minutes. Gotta love Giant Bomb.

"Well youtube and something awful do let'splays which are basically endurance runs. And people like Angry Video Game Nerd go back and take looks at classic games. "

Yeah 1UP has gamer nights but those are usually pretty long looks at a game (not to say that some QLs aren't as short as they should be).  And Youtube always has "gameplay" videos for many games including ones that haven't been released.  I don't know if Gamespot still does their weekly show, On the Spot with video previews.  I'd suggest taking a look at Area5/Revision3's video game show, Co-Op for footage of games in play. 

20 mins is about right for the quick looks, I wouldnt want them any shorter.
Do they often go much over that(> 5min)?

i guess you can loosely compare quick looks to those "Let's Play ______"  on youtube

No need to go to other sites.