One of the things I've slowly come love about London is the small "caff" and its humble, unhealthy, but oh-so-satisfying fryup. I just learned of a website that celebrates these:
http://russelldavies.typepad.com/eggbaconchipsandbeans/

Does anyone have special places like these that they would recommend?

Cuttle

Let's kill this preposterous myth stone dead.

There are indeed killjoys who think black pudding and fried slice are unhealthy. But where does all this "unhealthy" nonsense about beans on toast come from?

100% vegan. Lots of roughage. All the goodness of the cooked tomatoes in the sauce. If you're a health nut you can have some cholesterol-killing spread like Benecol. Or you can bake your beans in olive oiil and put them on bread (though that is, I agreee, a bit fey).

However you eat them, baked beans on toast are miles healthier than the junk - like croissants or pain au chocolat - nutritional illiterates poison themselves with.

And tastier even than the only edible breakfast the French have evewr devised - fresh baguettes, slathered with Normandy butter, dunked into bowls of chocolate.

Don't you dare diss our baked beans.

Ah beans on toast, the natural food of the student as was spag bol made from cheap mince, no doubt crawling with BSE.
I think that nowadays students live on takeaway pizzas.

Let me rephrase: does anybody have any favorite London spots wherein one can enjoy this fortifying and nutritious repast, good for whatever may ail you?

We stayed once in a British B&B that served us Spaghetti-Os for breakfast. They had a large Boxer dog. Guess who got a special treat when the owner's wife's back was turned.

Think it was Flanneruk who in a previous post i made about where to find typical greasy cafes in London - an endangered species it seems - that he, or maybe someone other London sage, said around train stations like London Bridge. I mentioned Lower Marsh Street tucked away behind Waterloo station. You'll find many more in non-posh areas like Camden. I'd agree that beans on toast sounds healthier than lots of fare London tourists grab if it weren't only for that grease or butter they lather on the toast.

Found one across from Marylebone Train station and next to the Landmark Hotel. Tried to find the name (unsuccessfully) but was rewarded with this wonderful list/website. Have a blast
http://www.classiccafes.co.uk/Criteria.html

For anyone wanting a fix!!! of beans on toast here in the US . most markets have Hienz Vegitarian Baked Beans & they taste just like they do in the UK.