Passenger satisfaction levels have dipped below 50% for the majority of train companies, according to a Which? survey of more than 7,000 regular travellers.
For two companies - Greater Anglia and Southeastern - the satisfaction score was only 40%.
Ten of the 19 companies had satisfaction scores of less than 50%, with Merseyrail (70%) the best-performing company.
The survey, conducted among 7,415 UK adults in November 2013 also showed:
:: 16% of all passengers experienced a delay on their last journey, with this figure rising to 26% for commuters;
:: 21% o f commuters said they were likely to have stood on their last journey:
:: 11% said toilets were not in good working order. This rose to 20% for London Midland , 19% for Southeastern and 17% for First Capital Connect (FCC):
:: 11% said they had cause to complain about the last journey they had taken, but 75% did not officially complain. Of those who did complain, more than half (55%) were dissatisfied with how it was handled.
The overall satisfaction scores were based on satisfaction with a company and the likelihood of customers recommending the company. On average, those surveyed had travelled by train 32 times in the previous 12 months.
Which? also asked what passengers felt would improve their journeys and what they would be prepared to pay more for.
Lower ticket prices were top of the wanted list (60%), with 80% saying fares were too high. People also wanted to see more carriages at peak times (35%), promotions on ticket prices (29%), wi-fi as standard (20%) and improved punctuality and reliability (18% - rising to 29% for commuters only.)
A total of 12% said they want cleaner trains, with FCC and Greater Anglia getting the lowest scores for cleanliness.
However, more than half (53%) said they would not mind paying more if they saw an improvement in service in return. Half (49%) would pay more for a more reliable service, and a similar number (48%) would pay more to guarantee a seat. A total of 42% would pay more if the money went towards new trains.
Which? executive director Richard Lloyd said: "It's disappointing to see some train companies consistently falling down on the basics of customer service, with dirty and overcrowded carriages and toilets that don't work.
"Seven rail franchises end in the next two years and we want to see passengers' experiences put right at the heart of the tender process so companies respond to consumer expectations and can be held to account if they don't."
These were the overall satisfaction scores by company:
1. Merseyrail 70%
2. Chiltern 69%
3. c2c 67%
4. Virgin Trains 64%
5. East Coast 59%
6. London Overground 58%
7. ScotRail 56%
8. CrossCountry 52%
9. East Midlands Trains 50%
10= First TransPennine Express 48%
10= Arriva Trains Wales 48%
12. London Midland 47%
13= Southern 46%
13= Northern 46%
15= First Great Western 45%
15= South West Trains 45%
17. First Capital Connect 41%
18= Greater Anglia 40%
18= Southeastern 40%
A spokesman for the rail industry body the Rail Delivery Group said: "As we acknowledged last month when the independent watchdog's far more comprehensive survey found that more than four out of five passengers were satisfied with their overall journey, the industry needs to build on the improvements it has delivered over the last 15 years.
"We are always keen to get feedback from customers, whether good or bad, which has helped the industry attract record numbers of passengers and cut complaints by three quarters in a decade."
Bob Crow, leader of the RMT transport union, said: "Once again this survey shows that Britain's privatised railways are delivering lousy service to the public while money that could be invested in capacity and upgrading is syphoned off into multi-million pound profits for the rich.
"(London Mayor) Boris Johnson should take note of the fact that the British people want ticket offices and properly-staffed stations which was the issue at the heart of the Tube dispute."
Rail Minister Stephen Hammond said: "As well as getting passengers to their destinations, operators should be working hard to improve the overall experience of their customers.
"Passengers have every right to expect trains to arrive on time and be clean, and while this can be a challenge, I expect operators to do all they can. "
He went on: "We are supporting this by investing billions in new state-of-the-art trains that will transform the customer experience across much of the network. This will mean more capacity, improved facilities and quicker and cleaner journeys.
"We are also putting customers at the heart of our new franchising system and for the first time ever passenger satisfaction will be considered when deciding which companies are awarded franchises."
Martin Abrams public transport campaigner for the Campaign for Better Transport, said: "The Which? survey shows deepening levels of dissatisfaction with many train services. Passengers want cheaper, simpler tickets, clean stations and an end to chronic overcrowding.
"We need to learn from franchises like Merseyrail and London Overground which have bucked the national trend. These show that investment coupled with a stronger local voice in how services are managed can significantly improve passenger satisfaction. "