We would LOVE to linger for hours in numerous museums and galleries in London, but tht would fill too many hours. Leaning toward British Museum. Any suggesions for a second or alternative? Archaeology and historical diversity a plus.

The Museum of London is very well-laid out, has a diverse selection of exhibits and and media, provides an excellent overview of London's history starting with the ancients. I would say 2-3 hours would cover it.

It's just a couple of blocks from St Paul's cathedral, between St P and the Barbican.

The British Museum is overwhelming to me, I'm good for a couple of hours and then I need a cuppa. Except for the Elgin Marbles, it is not one of my favorite museums, but it is important imo to get past the first floor to see the full range of what it has to offer.

I should have said, get past the ground floor, 1st floor is one up.

The British Museum has amazing archaeology and historic diversity - you should definitely spend time there. If you also want art, consider the National Gallery. It you prefer modern art, try the Tate Modern. If you like history and design, the Victoria & Albert is a good choice. The Fodor's London Destinations page has a good description of the museums.

I would definetly recommend the British Museum and the V&A. Both have excellent tours in various areas of the museum as well evening hours. Check out their websites as both offer more in depth tours, courses and seminars.

The Wallace Collection is a very interesting museum and one that not a lot of people know about. Also, the Cabinet War Rooms, and the opening-tomorrow Churchill Museum. I love the National Gallery and Tate Britain.

If you are interested in archaeology within London then the Museum of London is the place. They have a good collection and archaeology is a large part of their focus. The museum is well worth a trip. Check their website for special programs. The V&A is great for objects and their ceramics collection is one of the best around. I find the British Museum is best with some research beforehand so you know what you want to see and aren't just wandering aimlessly.

On the criteria you've given, there's only one alternative. The Museum of London has good archaeology (and is usually good on how archaeology works, as there's almost always a recent excavation featured) but it's not at all diverse. It's about London, and nothing else.

So unless there's an archaeology-inspired blockbuster (like the odd, but certainly historically diverse and long on archaeology "The Turks" currently at the Royal Academy), the only alternative to the BM is the Sir John Soane's museum in Lincoln's Inn Fields. It has reasonable archaeology, stuff from everywhere and every epoch and is capable of being seen through pretty quickly. It's one of the very few museums here you can do justice to without getting an attack of Museum Head. In fact it's really the only one, apart from the Wallace Collection, which is similarly individualistic and quirky, but is really limited to fine art.

The V+A is diverse to the point of near-insanity, but it doesn't do archaeology, apart from a few (but wonderful) excavations from Central Asia. Though if you've never been exposed to the glories of Gandharan art, this is place to discover it.

The real answer to your question, though, is to buy Time Out at the airport when you arrive (or preferably before you leave home) and go through their thumbnail sketches of the major couple of dozen museums, and their current exhibitions. Inevitably, you'll be collectively drawn to something quite different from the brief you've given us.

We enjoyed the 200 Treasures Room at the British Library. It has the Gutenburg Bible, Magna Carta, original manuscripts from Handel, Mozart, the Beatles and Lewis Carroll (Alice in Wonderland). It made a memorable stop on a rainy afternoon.

One more comment regarding the British Museum - it is open, I think, Thursday and Friday evenings. It is not nearly as crowded and you'll even have some areas all to yourself.
One other bonus - it's free admission.
JoeG

Thank you all very much for the helpful input. It makes choices much less daunting.