What sort of crap would you recommend to do in London (and general area) if you had 3 days to kill? Wife, 3 kids and two in-laws will be there. Touristy crap but don't want to get stabbed.
Bodybuilding related: I'm wider than Heath.
You can actually visit a few countries at the same time if you go to the right places.
Visit Southall and it is just like being in India.
Visit Brixton and it is just like being in the Caribbean.
Visit Newham, it is just like being in Nigeria.
London has so much to offer.
Reality is if you are there for 3 days with the family and have never been there before you might as well stick to the tourist routes.
Touristy crap = Big Ben, Houses of Parliament, Tower of London, London Bridge. Do the Natural History Museum its massive, Science Museum, dont bother with any of the others. Buckingham Palace.
Dont waste time trying food, if your coming from most other countries, the eating experience at 90% of places you find will be mediocre. If you see a chain you like, you might as well just go there.
For transport get a travel card so you can use underground, buses, DLR without having to worry about different tickets. Heres a link, you only need zones 1-2 to see 90% of all the tourist sites. No point going further a field, better stay central as that way you can develop an unrealisticly enjoyable tourists view of what life in london is like.
http://visitorshop.tfl.gov.uk/tfl/london-travelcard/