We're planning to go to London for 4 days in December. It costs the same amount to fly into Stansted as to Gatwick. Which airport is easiest to get to downtown from?
Gatwick is probably the easiest for most visitors, just get one of the various trains into Victoria, London Bridge or St Pancras - whichever is nearest your hotel.
Stansted is further out and the rail station in London Liverpool Street is in the financial area, far away from where most visitors to stay.
However the various bus services can be cheap.
There are tables of the various costs of your options and journey times at:
www.londontoolkit.com/travel/gatwick_transport.htm and www.londontoolkit.com/travel/stansted_transport.htm
gatwick is easier to get to downtown, 15min to victoria station with gatwick express, and 30 min to victoria station with southern train, if you want to save money go with southern train.
Gatwick Express goes from the airport to Victoria Station in 30 minutes. Trains operate every 15 minutes.
I don't mean to sound like a broken record, but fly into Gatwick. We had the choice to fly in and out of Gatwick, or fly out of Stansted and into Gatwick. I chose the latter (liked the time of the flight better) and regretted it. It is so much easier to get back and forth to Gatwick.
I've always been happy with Gatwick, never flown into Stansted.
We just had the experience of flying Easyjet into Stansted--we had no choice. We took the Stansted Express rather than the train that would take us to Liverpool Station. The bus took a very long time and stopped in several small towns. When we finally got into the London area traffic was awful. So yes, LGW would be a better choice.