Sandown pier on the Isle Of Wight has a huge arcade, the biggest on the island i think.
Also there is an arcade opposite the train station at Ryde seafront which has a ton of retro machines and is also kinda big.
I live on the island mate, I go down to Sandown pier every weekend if I get the chance. I rarely go to Ryde though... maybe we could meet up one day and play on a few machines at Sandown?