The 7.44am service from Henley-on-Thames to London Paddington is officially the most overcrowded commuter train, running a staggering 80 per cent over capacity.
The First Great Western Service from the Oxfordshire town carries almost 180 more passengers than its 225 person capacity, giving it a 'load factor' of 180 per cent.
The packed service was 80 per cent over capacity in standard-class carriages when the survey was carried out in autumn of last year.
Second in the list of overcrowded trains was the South West Trains 7.32 service from Woking, Surrey, to London's Waterloo station.
It carried 471 more passengers than its capacity of 738, putting it 64 per cent over capacity.
The services in third and fourth were both from London Euston to Birmingham New Street.
The 6.13pm service was 62 per cent over capacity, cramming an extra 431 passengers on board, while the 4.48 train was 60 per cent over capacity.
Passengers are likely to be even more frustrated by the data given that, as of January 2, Henley season ticket holders will see their annual fare increase by 4.18 per cent to £3,388.
Services from Banbury to Paddington, Stourbridge, West Mids to Stratford-Upon-Avon, and Manchester Airport to Middlesborough also featured in the top 10.
Train from London Liverpool Street to Shenfield, Alton, Hampshire, to Waterloo, and the 5.46 from Euston to Birmingham completed the list.
It should be noted that, since the data was collected, First Great Western added a carriage to the 7.44am service from Henley to Paddington, taking the number of standard class seats to 340.
The figures were revealed as it emerged that some train companies are running fewer than 60% of services on time.
According to 'real' punctuality figures, CrossCountry, whose services snake around Britain, managed a punctuality rate of only 48.8% over the last year.
The CrossCountry figure, relating to the 12 months ending December 8 2012, is contained in new information released by Network Rail (NR) as part of "right-time" data on punctuality.
Under this criteria, trains are considered late if they arrive more than 59 seconds after the timetabled time.
Other companies to run fewer than two in three trains on time under the right-time criteria are Southern (56.9%), First ScotRail (59.7%), London Midland (65.7%) and Southeastern (65.8%).
Under this particular measurement, the national average for punctuality is 69.2%.
Transport Minister Norman Baker, who released the data on train overcrowding, said train operators were 'aware of the overcrowding'.
He said: "Climbing on a crowded train where there is little space can often be an unpleasant experience and I sympathise with passengers who have to travel on these services.
"The operators on the list are aware of the crowding problems on these particular services.
"I will be monitoring these services closely, and others which have not made the top 10 list, and urging train companies to reduce crowding on the busiest services."