Pacers were great before the rebrand, but the addition of the stripes was a negative in my view.
Double Agents were awesome and I have no idea why they suddenly vanished from shelves.
Old English Spangles, which were great because other kids hated them so didn't bother me.
The opaque green Spangle in the fruit version, which I think was actually supposed to be Grapefruit flavour.
Texan bars. Still nothing comparable to the original. They were garbage when they relaunched. Half the size, and nowhere near as hard work to chew.
Splicers. Probably banned because of profligate E-number use, but I didn't care. It was like having a giant, elongated Opal Fruit bar, with no pesky wrappers to spoil the fun, and actual proper zingy flavour, not the dreary "is that it?" opal fruits let-down.
Gold Rush bubblegum, with the wee bag made to look like a hessian sack.
Dinosaur Eggs, the watermelon flavour.
More recently, I will never forgive them for withdrawing plain chocolate Bounty. The milk version is foul.