EDF, npower and Scottish Power were given the worst star rating by Consumer Focus for the number of complaints they received in relation to their market share.
Scottish and Southern Energy (SSE) came top of the league table with four stars, while British Gas and E.On both received three stars.
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Hide AdThe consumer watchdog ranked the "Big Six" energy firms to help consumers decide which supplier will give them the fewest problems or best handle any complaints.
Consumer Focus said the Big Six received 4.6 million complaints in the last financial year.
Mike O'Connor, chief executive at Consumer Focus, said: "We know energy companies are rooted at the bottom of our consumer trust survey."