Bill's is good for breakfast. I have also been assured by friends that it is good for lunch and dinner too, but I started with breakfast, and it was goo-ood. Eggs Florentine, full English, porridge, French toast, juice, smoothies, Bloody Marys, take your pick, everything we ordered (and there were six of us) looked and tasted delicious. Okay, so we didn't order the porridge, it was a Sunday morning and a birthday breakfast for chrissake, but everything else was delicious and I am sure the porridge would have been too, had we been feeling a little more restrained.
Bill's also sell grocery items, and it is worth a visit for the beautifully stacked and wonderfully colourful shelves alone. Also, branches in Brighton (the original I think, never been, but told it's fab), Cambridge, Lewes and Reading, so if you are not a Londoner you can still get your fix.