Foridden planet yes, it is a bit out of the way but it's very good. Easy to sink hours into and to drain your wallet if not careful.
I say
avoid some of the more touristy attractions in London such as Madame Tussards and the London Eye as they're not worth it and overly packed.
Camden Lock is pretty good but really more of a touristy attraction these days compared to it's seedy rebelious origins, mostly full of cheep sunglasses, hats and quote un quote "ironic tees" you know those unfunny tee shirts with pop culture refferences that weren't funny 2 years ago. But there is good stuff there and the food in particular is great and just wondering by you'll get plenty of Chinese girls giving you free samples of curry ect.
Brick Lane is very good and better than Candem these days when they've got the market going. Once just a place for people to sell old CD and videos on the street corners now a burgeoning market place and probably the coolest place to be in London. Great food, great vibe and atmosphere, wonderfully multicultural. And its the home of Rough Trade the coolest record shop in the world, they sometimes do free gigs there with artists promoting their work. They'll be incredibly rare and always in high demand when they do but it's something to look out for.
If you're into films go to the BFI centre on the southbank, full of indie and forgeign films in the gift shops as well as more films books and guides that you could ever need. They also sometimes do screening there of films. You probably wont have time for this and not everyone is as into films as I am but whatever.
If you don't want to see a film avoid Leicester square cinemas, there is loads but they are all incredibly expensive and not worth it even if it where they do the red carpet premiers. But the expection to this rule is a, for lack of a better word, quaint little cinema with very reasonable prices, atleast for London, called Prince Charles Cinemas. It's down an alleyway off of Leicester square and has a sign saying "Tickets From £1" outside, that is only for members and on latenight retro screenings but still.
I'm shocked no one has mentioned this yet but HARODS! Biggest best most expensive shop in the world! 8 floors and full of everything you could imagine! Solid gold football tables, scuba scooters for £80,000, golf buggies for £18,000, a pet store with the cutest poodles in the shop! It goes on, its well worth a look even if you aren't an excentric billionare, just seeing what there is brilliant fun.
I can't think of much more right now. If you're legal drinking age go out clubbing or to a pub, some great huge pubs and clubs in Candem. Worlds End is the one where everyone goes and I literally mean everyone, so it will be packed.
So enjoy London, my favourite place in the whole world. Oh and as a passing message, what with you being a tourist and all... ahem.
STAND ON THE FUCKING RIGHT WHEN YOU GO UP THE ESCALATORS ON THE TUBE, THERE IS NO EXCUSE NONE WHAT SO EVER FOR FAILING TO COMPLY WITH THIS SIMPLE FUCKING RULE. AND IT IS ALWAYS TOURISTS WHO DO IT!
So that aside have fun

and pick up a copy of Time Out London, you'll look cool for buying it plus it might have some of my sister's art work in it so you'll be giving her money.