London Stansted Airport (STN) to Southampton Central (SOU) train

South Western Railway is a train operating company in the United Kingdom, providing services in the south and south-west of England. It operates a variety of train types, including high-speed trains, local stopping services, and suburban commuter trains. It also offers a range of ticket types, including Advance, Off-Peak, and Super Off-Peak tickets. Onboard facilities include free Wi-Fi, power sockets, and a range of food and drink options. The most popular routes for South Western Railway include London Waterloo to Portsmouth Harbour, London Waterloo to Weymouth, and London Waterloo to Bournemouth.

Tfl Rail is a railway service operated by Transport for London in the United Kingdom. It operates on the Great Western Main Line and the Heathrow branch of the London Underground. The service runs from Paddington in London to Reading, Maidenhead, Slough, and Heathrow Airport. It also serves the towns of Taplow, Burnham, Twyford, and Hayes & Harlington. All trains are air-conditioned and feature onboard Wi-Fi, power sockets, and digital information screens. Tfl Rail offers a range of ticket types, including single and return tickets, season tickets, and Oyster cards. Oyster cards are the most popular ticket type, allowing passengers to pay for their journey with a single card. The most popular routes for Tfl Rail are Paddington to Reading, Paddington to Maidenhead, and Paddington to Heathrow Airport. These routes offer frequent services and provide passengers with a convenient way to travel between London and the surrounding areas.

Greater Anglia is a train company based in the United Kingdom. It operates a wide range of services, from commuter trains to intercity services. The commuter trains run at regular intervals throughout the day, while the intercity services run at peak times. The train types include the InterCity 125, InterCity 225, Class 90, Class 91, Class 360 and Class 379. The ticket types available are Standard, First Class and Advance. Onboard facilities include Wi-Fi, power sockets, air conditioning and refreshment trolleys. The most popular routes for Greater Anglia are London Liverpool Street to Norwich, London Liverpool Street to Cambridge and London Liverpool Street to Ipswich.

Cross Country trains are a UK-based train operator that provides services across the country including trains between London Stansted Airport (STN) and Southampton Central (SOU). They offer a range of services, from express services to local services, and have a variety of ticket types to suit different needs. Their express services, such as the CrossCountry Voyager and CrossCountry XC Trains, offer a fast and comfortable journey, with onboard facilities such as free Wi-Fi, power sockets, and a selection of snacks and drinks. Their local services, such as the CrossCountry Regional and CrossCountry Regional Express, provide a more leisurely journey, with stops at smaller stations along the way. They also offer a range of ticket types, such as Advance, Anytime, and Off-Peak tickets, to suit different budgets and travel needs. The most popular routes for Cross Country trains include London to Birmingham, Manchester to Edinburgh, and Bristol to Reading.