London's Airports
If you travel to London by plane, you will arrive at one of the following six airports.

Heathrow:
London's most famous airport is one of the biggest airports in the world. A large number of airlines serve cities all over the world, so if you're coming in from the USA or Australia, you will be likely to land there. Heathrow airport is located southwest of London, still its connected to the Tube system. This makes getting to the city center inexpensive. Since you will have to buy a daypass for the Tube anyway, just go with a Travelcard Zone 1-6 and you're covered. The Piccadilly Line will take you right to Piccadilly Circus, however it will take about 45 minutes. If you're short on time, yoou might want to take the Heathrow Express to Paddington, which is a 15 minute ride. However, a return ticket will cost you as much as 29 Pounds! A third option would be a busride with National Express. The return fare ist 8 Pounds, journey time is about an hour, depended on traffic.

Gatwick:
Gatwick is London's number two aiport. The train is the best option to get to the city center. The regular train costs about 10 Pounds for a one way ticket, journey time is approx 30 minutes. There's also an express train, however it's not really faster and the fare is a lot higher (28 Pounds return). If you're trying to save money, the bus is the right option for you (National Express). The ride takes about 80 minutes to Victoria, but on a more positive side, the fare is just 15 Pounds return.

City:
London City is the airport that's located closest to the city center. The Dockland Light Railway connects it with the Tube system. The airport is situated in travel zone 3, so a Travelcard for zones 1-4 covers your journey into the city center. Journey time to Bank are approx 20 minutes. If for some reason the DLR's not running, you can also catch a bus to Canning Town which is on the Jubilee Line. In addition, there are express busses running to Canary wharf an Liverpool Street Station (not included in the Travelcard!). If you have the choice, London City is by far the best airport to fly to. Not only because of the short journey time to central London, but also because check-in and boarding are extremely convenient.

Stansted:
Stansted is the hub of low cost airline Ryan Air and many other low cost airlines.The term "London-Stansted" is a bit misleading, since Stansted is located far beyond London's border. To get to the city center, there are basically two options: train or bus. There's an express train running to Liverpool Street, which takes as little as 45 minutes and costs as much as 24 Pounds. A slowler but cheaper alternative is a bus ride. Depended on traffic, the journey time is about an hour. Fares are approx 14 Pounds for a return ticket (National Express and Terravision).
Good news: Starting June 2007, there will be an EasyBus Service between Stansted and central London. This means, that for the first time, it has become affordable to travel between the airport and the city center. When booked in advance, a one way fare can be as low as 2 Pounds! However, these cheap seats are limited. Once the capacity is booked out,fares go up to 4, 6 and 8 Pounds. The walk up fare is the same fare the other bus companies offer (14 Pounds). Keep in mind: If you're travelling with a lot of luggage, you might have to reserve two seats for the EasyBus!

Luton:
Besides Luton Town FC, the city of Luton also features an airport. It's the hub for low cost airline EasyJet. So of course, there's an EasyBus service between the airport and central London. Fares are between 2 and 8 Pounds (single), when booked in advance. Additionally there's also a GreenLine bus running, which costs about 14 Pounds return. Both bus services take approx an hour to central London. If you want to get to the city center faster, you can take the train to King's Cross St. Pancras. Journey time is only 30 minutes, however a return ticket costs 20 Pounds.

Car

Going to London by car is a good option if the distance is short and you're travelling with more than two people. Biggest obstacle is, of course, the channel, which you have to cross. There are two options: you can either take a ferry (approx 40 Euro one way) or you can take the train through the channel tunnel (approx 75 Euro one way). The train's a lot faster, but as you've noticed, it's also a lot more expensive.

To plan your journey, just go to maps.google.com.

IF you decide to go by car, you have to be aware of some problems. First of all, you have to drive on the left side of the road. Sure, this is totally weird, but that's how the English like it. What can you do. Then, taking the car into London is difficult. Not only because of the traffic. First, you will need to pay a Congestion Charge that will allow you to actually drive through the city center. Secondly, you've gotta park your car somewhere and that's not easy. If your hotel doesn't offer parking spaces you're in trouble. Finally, keep in mind, that gas is expensive in Britain.

Rail

Of course you can also get to London by train. Most connections from Europe will take you to Paris or Brussels from where the Eurostar is departing to London. You can also check your national rail's website for special offers or get an interrail pass.

Bus

Fear of flying, no drivers license plus you hate trains? Don't worry, here's a plan for you: Go by bus. There are basically two options. Many bus companies offer weekend (or even longer) trips to London. Usually these trips aren't very expensive and as a bonus, you don't have to worry about accommodation. As a second option Eurolines has bus routes all over Europe, including the UK.