In reply to Bill Davidson:
Illy is overrated....Lavazza if you can get it is far better.
Of the chains Pret is the best.
The test of a cafe's coffee is the straight espresso....if it is drinkable that is a good start, if not why bother. Sadly it is quite easy to take a crap shot of coffe then disguise it with milk and sugar and sell it to uneducated punters.
I would posit that 90% of UK coffee drinkers wouldn't know a decent cup of coffee if it bit them on the arse.
That is still better than the US at 99% for the same statistic.