I've got to say that i find my local Tesco almost perfect. Everything i need under one roof at competitive prices and good quality. In and out in less than 20 minutes, as a rule, and most of the staff are very friendly and helpful. Except the grumpy one who works on the lotto counter:-)
Old ladies that go part way in through the front doors and then stand there, gaping around them, like they have never seen inside Tesco's before, and consequently block the way for everybody else !
It's not the people that irritate me so much. I hate getting the trolley, I hate putting the trolley back, I get impatient if I can't find something, even more impatient if I then can't find a member of staff, don't like unloading the trolley and packing...and I hate putting it all away when I get home.
The "fast lane". Those self service tills where you have to hang around and wait for someone to authorize your beer purchase. I'll 'unexpected item in the baggage area" you in a minute, stupid crappy system that doesn't work.