I got a decent sandwich from a garage the other day, can't remember if it was an esso or shell, but they had boxes of 3 sandwiches for £2.50, and I was really surprised at how good it was-bread was fresh, meat seemed to be good quality, NO MAYO, and juicy lettuce.
Tesco ones are usually (but not always) OK as well. But avoid ones from Sayers like the plague!
But Sub is the only Way to go for sandwiches really.
Pack your bags
And come aboard as we hoist the Black Flag...