Rather than one individual website, this is a whole genre of websites. The premiere place would be Keenspot.com, featuring such diverse strips as philosopher foxes, adorable sheep, and murderers. Essentially, they’re like regular comics, but completely on the internet. Every one of these webcomics is filled with backstory and could take you hours to finish. You’re welcome.
Keenspot.com
Penny-Arcade.com
DieselSweeties.com
LeastICouldDo.com
Sinfest.net
XKCD.com
Update: If you REALLY are looking to kill time, check out The Web Comic List. But be warned, this list is long and potentially terrible.
