My original, unique, one off, official Levellers 'subvert' t-shirt, which i've had for the best part of 20 years. Although it is looking worse for wear, I wouldn't dream of getting rid of it, it's been round various countries in Europe with me and has been the catalyst of many longstanding friendships being formed, mainly due to the unusual text written on it being a such a great conversation starter, it's seen me through a heck of a lot of seriously good times and bad and has many drops of my own blood, sweat and tears embedded into it, as well as a few ancient cookie holes, paint and various other things.
I can only wear it in the house now though, as i'd get funny looks wearing a t-shirt with holes in it, in the state it's now in, walking down the street.
My next favourite clothing item is my Sunderland AFC shirt for obvious reasons.