I always used to eat Golden Wonder. My Uncle worked at the factory in Widnes and brought home literally hundreds of packets a month (plus Pot Noodles, Pot Puddings, etc). They were the "top" crisp in the UK at the time before Walkers started making an in-road.
Quality difference is actually incredible. There was no real quality control, so packets would end up with no flavour on the crisps, but a flavour bomb in the bottom of a random packet. The crisps would quite often be a bit soggy from being cooked in too cook oil or burnt to a, well, a crisp.
It's no wonder Walkers came in and, well, walked all over them.
I love Seabrook crisps though, they're like Golden Wonder used to be when you could find a good packet. They appeared in our college around 1991 or so and seemed to be an academic institute issue crisps (they also made there way into Staffs Uni vending machines a couple of years later. Their prawn cocktail are probably the best on the market. Not too strong (unlike Walkers).
I also love Square crisps. The Salt and Vinegar are mouth bleedingly strong (unlike prawn cocktail, salt and vinegar should be strong), the plain are fantastically potatoey and even the cheese and onion is palatable.
Finally, Rib'n'Saucey Nik Naks are possibly some of the best crisps ever produced, addictively delicious and a fun shape to boot.
In terms of the actual "crisp quality", Walkers are the best. The potatoes are clearly good quality and they have a fantastic cooking and flavouring system across the board - so they're all produced to the highest possible quality they can manage. However, I like the odd-ball stuff just that bit more