I must have about 30 plastic/virtual cards and the only ones I ever seem to benefit from are Tesco, Boots and Waterstones mainly. Nectar and Morrisons for the odd shop and occasional £5 off.
TK maxx - what is the point? Superdrug - every time I've checked I've seen an expired reward. M&S - money off things I've either literally just bought or would never buy (meat when I'm vegan).
Any decent/terrible ones? I'm going to cut up the rest I think.