io9 Flashbacks can be funny things. The disclaimer is tucked ways away down at the bottom of the post, and sometimes you'll be 3/4 of the way through when you start to think 'waitaminit... haven't I seen this somewhere before?' and start wracking your brain for your most recent browsing history.
However, when the Powers That Be reposted this nastiness earlier today, I knew right away that an older piece had been bumped up, if only because the gif they led with has been seared indelibly into my memory.
It's such a striking image that it'll probably stick for quite some time, and, given the high rate of turnover on the front page, that's saying something.
What stuck for you? Which io9 posts are the cream of the crop? If you were going to convince a friend to start reading io9, what would you definitely point 'em towards as a can't-miss, must-read exemplar of the kind of writing that goes on over on the mainpage?