For me, it's Tescos.
Simple reason - I was on my way home from work last winter (office job, so well dressed) and popped into local large Tesco to pick up something. Was innocently wandering around when I got a tap on the shoulder - it appeared to be a staff member (so having my headphones in) didn't hear what he said, so just replied, 'No, I'm fine thanks'. He taps again and I took headphones out and he said 'We have a NO HOODS POLICY in the store'. I took my hood down but was secretly seething - FFS, it was sub zero outside and I'd just come inside.
So I'll do everything I can to avoid Tescos.
Any others?