Coach service
National Express operate a coach service to London. This is an inexpensive option, but slow, taking nearly three hours at some times of day to cover the distance.
Operating hours are good. Fares are maybe £9 per person.
The final destination is Victoria Coach Station, though there are intermediate stops on the way, including Hammersmith and Heathrow!
It may be cheap, but, after a flight of any length, we want to get to our destination as quickly as possible.