Quite a few spring to mind but the most sensible and honest answer is the Boys of ’86 shirt. We had such a great season with that shirt, nearly winning the league. I was in Prague in June when West Ham won the Conference League and it was amazing how many fans were wearing that iconic top. It resonates with, shall we say, the more mature fan.
It was a very simple but different top, away from what we usually wore at West Ham. A standout memory from that season is beating Chelsea 4-0, but we wore the white away kit.