My current chair that I use I found in a bush this one time, its like a big office style chair with one of the arm rests missing, but believe me that's one hell of an upgrade from what I was previously using.
My previous chair had lost its back rest and the actual bit you sit on managed to come off at one point, so one day on my way home I saw a chair in a bush so I started wheeling it home (not before I took it down the ramps of course) and I got many strange looks, this one drunk guy outside a pub actually got on it and started shouting "WAAAAAAYYYYYY" to the amusement of his friends, but anyway this chair has served me well since.