Third Class
is not too bad, but you are not guaranteed a seat (or upholstery on the seat), and the fans do not always work. In some carriages seats are upholstered and, if the train is not crowded (which they usually are) the trip can be quite pleasant; some trains, and most trains from Thonburi station to Kanchanaburi and the 'Death Railway', have wooden benches only. On the Eastern Line, third class travel is compulsory except for two trains a day to Chachoengsao, which offer 2nd class air-con.