topping. thanks!

Ha! This thread is old, but I feel compelled to add my two pence...

Must see:
Bath (best city I visited)
Stonehenge and Avebury (Mad Max Tour is awesome)
York

Nice but don't bother:
Oxford
Stratford-upon-Avon (unless you're a Shakespeare fanatic)

One problem many travelers have is focusing on what they will miss rather than on what they have planned to see and do. Given the length of your trip (but no information on where or when you are going), here are my thoughts:

Brits spend many of their holidays renting a house/cottage/flat, etc. by the week. It is usually Friday - Friday or Saturday - Saturday. Choose three separate locations in the UK and make that place your base for each of the three weeks. Check out the sights in each of the three separate locations and don't worry about what you are missing. Each area has its own local sights in addition to the major sights as being your reason for being there. Let each of your kids choose 2 or 3 of the activities so that they can choose what they want to do.

With this in mind, a couple great locations to set up base are St. Ives (great place) or anyplace in Cornwall. From there you can see, St. Michaels Mount, Penzance, Land's End, Newquay, castles, national park, beaches, etc.

Or you can choose the York area and see Hadrian's wall, Lake District, York, castles, etc. and surrounding areas.

Liverpool area - Wales, Beatles, castles, etc.

Travel to these places may include stops at Stratford Upon Avon, Oxford, Bath, etc.

You can not hit only the must sees whithout having to do a lot of unnecessary traveling. Again, don't worry about what you are missing. Focus on those attractions which allow you to have a fun family trip.

I have to put my two cents in for Stonehenge. Try to book an "after hours" tour when you can walk in amongst the stones with only a small group of other people. It was one of the highlights of our family's trip and my kids (ages 17 and 14) were thrilled to be able to touch the stones they have seen in their history books.

Having spent more time out in the countryside in the UK I'm starting to think that London may fit into the "nice but don't bother" category!

I'd second that Dukey!

Everybody's memories of what was special will be different - depending on what their particular interests are; whether they got out of the wrong or right side of bed that particular morning!

There is so much to see you might do better to divide possibilities into tourist traps (OK they are popular for a reason) - but do you like tourist traps? Places a little less visited but easy to get to: and places for those who don't want to see a tourist coach all day.

It's hard.

Pick one of Bath, Oxford, Cambridge, Stratford. All totally overrun.

The Lake District is crowded; the North Yorks Moors are stunning; ditto Dorset (far less visited by people from overseas I guess than Devon, Cornwall, or North Wales.

I haven't said much about Scotland because I know it less well than I should.

If it were me - go North. York, Durham, the Moors. Get a car and an OS map and take the smallest roads there are. Or go south and check out Salisbury, Dorset in general and Devon.

2001 date..Try a canal boat trip. Either a manned one or a do-it-yourself trip. Sports courses abound and are great fun...canoeing, kayaking, football even skiing. Inquire at the British Canoe Union. Brits do 'walks'. Try some of the 'small rail trips'.

It really is downright ridiculous to describe Oxford as "totally over-run".

I'm in the town several times most weeks: it's got a crowded (and horrible) main shopping street - but who (apart from the city's inhabitants)goes to Oxford to check out BhS vs Debenhams?

Other than that, when I go to service or evensong at Christ Church, it's as empty as a tomb. When I pop into a library to check a piece of data, everywhere's devoid of people. If I go and buy something away from the main chavstreet, they're all crowd free. Wander along the river before getting a train - same thing.

If the poster with the weird sense of crowds is as poor a judge of Bath, Stratford and Cambridge (and whenever I'm in Bath I hardly feel it's been taken over by hundreds of thousands of people), the rest of you may visit all these places with perfect equanimity.

The only two places I visited in London that I feel I could have skipped were Covent Garden and Harrods.

Covent Garden is just a (slightly) larger version of Faneuil Hall or South Street Seaport, IMO.

I would like to go back to Harrods to see if I missed something amazing. I was there with my kids after a very long day of sight seeing, so their fuses were beginning to burn short and I was mindful to get out before a meltdown happened. Based on what I saw, other than the food halls -- which were awesome! -- it's just a department store.