Tons of stuff. Im a hoarder so keep everything. Still got all my season tickets and match tickets, sold a lot of programmes, but kept a few specific ones like my first games, Cup Finals etc. shirts, signed things, stuff from European aways. The two most sentimental things I have probably though are a baby kit I bought for my niece for her 1st birthday, which both of her brothers who came after her have all had on! They have all grown out of it now, but I still have the kit! The other is my scarf. I bought it at my second game, Arsenal at home in 99 when I was 13 and its been everywhere with me since. Everything Ive seen, everywhere Ive been, my scarf has seen it too.