You know it's a good speedrun when it gets me to let out an audible "Whaaat?" I lost count. Believe me when I say that this record-breaking Half-Life 2 run by the SourceRuns Team is a good one. Actually, I'm probably vastly underselling it here.
You wouldn't think a time of 1:27:51 would be possible in a game like this, but they always seem to find a way. To achieve that time, the run took multiple team members playing in 200 segments across 600 days. It's tough to fathom not only the knowledge needed to be able to pull this off, but the sheer ability required to execute on it.
Check out the YouTube description for a bunch of relevant links.
[Via PCGMedia -- Thanks, T3HM0RR0W]