The following list is drawn from memory, on the basis that if I can recall them with fondness, they're most likely worth a visit:
1. Houses Of Parliament.
There are very fine buildings. Admittance is free, but you may have to queue. Due to security searches, you may not be able to get in at all, as they have to let the Members Of Parliaments (MPs) and their guests in first. The searches can take time.
However, it's worth the wait. The interiors are very grand indeed, and the staff are friendly.
2. Statue Of Eros, Piccadilly Circus.
This is the geographical heart of London. The statue itself is handsome, but it's more just to say you've been there. The only other interesting feature is the neon advertising hoarding adjacent. This, and Leicester Square, are not much frequented by native Londoners; you will only meet more tourists in these places.
3. London Eye (or The Millenium Wheel).
It offers excellent views of central London, and is quite romantic on a clear, moonlit night. This needs to be booked in advance, otherwise you may not be able to get on. You can book this novelty online.
4. Tower Bridge.
This is best traversed by night, and in a London black cab. A fine example of Victorian workmanship.
5. Tower Of London.
Here are kept the Crown Jewels. This are impressive, but most impressive for me was a brief film clip shown there of the coronation of the current Queen Elizabeth. A very moving piece of ecclesiastical theatre.
Other than that, the ancient weaponry displayed has a kind of thuggish dullness about it. Also interesting are the ravens, who have their wings clipped to stop them flying off. You may see them hopping about outside.
6. A Red Double Decker Bus.
You can pay a small fee, and travel on one of these for a few stops. A pleasant, interesting and efficient means of transport.
7. The Tube.
This is the underground train system. In itself it's not remarkable, but it enables the ignorant tourist to pop up like a gopher at their destination, instead of negotiating the buses and the streets.
8. A Black Cab.
One could see the sites mentioned above in a black cab, at night. This is a high-quality, licenced taxi service, and a nice, if expensive way to get around.
9. The Side Streets.
Get off the main streets like Oxford Street and Charing Cross Road, and travel in parallel on the side streets. You'll see more of the real London, and you'll be pleasantly surprised at how much less crowded it is.
Likely to disappoint: Buckingham Palace, Oxford Street, Westminster Abbey, Trafalgar Square. I'm afraid these are not as interesting as their propaganda. One would go to see them just to boast you'd been.
You should get: 'The A-Z of London'. It is sold at any newsagent. This is a handy book of maps, with a good index. Even native Londoners find it essential in finding unfamiliar places. Don't leave your hotel without it; you might think you know the way, but you'll likely get lost, and even the locals may not know where you need to go!
