Having used the DC Metro quite a but when I lived in Baltimore and worked in Northern Virginia, I find stories like this one from Metafilter pretty interesting.

Is Something afoot at the DC Metro’s Crystal City station? First its the mysterious derailment on Tuesday, still unexplained. Now a strange man is spotted with vials of a unknown liquid in the station before the system is even open! What’s up at Crystal City?

My favorite weird DC Metro experience were the occasions when I’d be on the same car as the singing Korean. He is this Korean guy who rides the DC Metro during the morning rush, gets on a subway car, sings a single verse of a hymn until the car arrives at the next station, exits the car, and gets back onto the next car and repeats the whole scenario. He rules! He’s been blogged here.