I have some Fruit of the Loom, cotton T-Shirts going back to uni times, '92-'96. They're in one piece, but slightly stretched. I don't tend to wear them out in public anymore though - they've become my slob around the house, doing housework/DIY work wear.
I have fleeces and 'technical Ts' that are as old and still look good.
I have a couple of hideous shirts from the late 80s, early 90s that are still wearable, but I'm waiting for them to come back into fashion and wouldn't currently be seen dead in them. They make me smile whenever I open the wardrobe and see them - I instantly get sent back in time.
My problem is I tend to buy quality clothing, not cheap tat, so they don't wear out. They're replaced because I want something new. But I don't throw the old stuff away and therefore have overflowing wardrobes.
I need to be more ruthless.