Apparently yes, in a 2006 poll conducted by TripAdvisor, they were voted the "least favourite airline"
Furthermore, out of all the airlines in Europe, 24% of complaints were about Ryanair.
They have often been criticised about their misleading and adverts and have been taken to court on many occasions.
they are apparently an agressive airline, and make agressive contracts with airports by paying exceptionally low fees and when renewing contracts threaten to withdraw services with an airport.
Oh and 60% of all complaints to Ireland's Commission for Aviation Regulation were about Ryanair.
here are a few quotes which you can find on http://en.wikipedia.org/wiki/Ryanair
"Critics have attacked its hidden "taxes" and fees, and limited customer services, and charged that it practises deceptive advertising. In October 2006, Ryanair was voted the world's most disliked airline in a survey by the TripAdvisor website, with easyJet second. In November 2006, it was revealed as the subject of more complaints than any other airline in the EU.[3] 60% of all complaints to Ireland's Commission for Aviation Regulation were about Ryanair, amounting to 4 complaints per million passengers per year."
Ryanair's advertising has been considered offensive, occasionally even finding sanction from the courts.[22][23][24]. Ryanair was ordered by courts to pay damages to Carla Bruni, and French president Nicolas Sarkozy for using their images in advertising without permission [25].
One of their ads used a picture of the Manneken Pis, a famous Belgian statue of a urinating urchin, with the words: "Pissed off with Sabena's high fares? Low fares have arrived in Belgium." Sabena sued and the court ruled that the ads were misleading and offensive. Ryanair was ordered to discontinue the ads immediately or face fines. Ryanair was also obliged to publish an apology and publish the court decision on their website. Ryanair used the apologies for further advertising, primarily further price comparisons.[4]
"Another of their ads featured a model dressed up as a school girl accompanied by the words "Hottest back to school fares". After receiving 13 complaints, the British Advertising Standards Agency told them to withdraw the advert in the United Kingdom, saying that it "appeared to link teenage girls with sexually provocative behaviour and was irresponsible and likely to cause serious or widespread offence". Ryanair said that they would "not be withdrawing this ad" and would "not provide the ASA with any of the undertakings they seek", on the basis that they found it abstract that "a picture of a fully-clothed model is now claimed to cause 'serious or widespread offence', when many of the UK's leading daily newspapers regularly run pictures of topless or partially-dressed females without causing any serious or widespread offence"
Ryanair staff have been accused of behaving rudely to passengers. They have been accused of using foul and offensive language and attempting to grab a boarding card from a passenger[33], behaving in a menacing manner towards passengers[34] and rudeness towards a passenger who asked for a non-alcoholic drink after passengers were kept in a plane for three hours due to a delay [35].
"The airline has come under heavy criticism in the past for its poor treatment of disabled passengers. In 2002 it refused to provide wheelchairs for disabled passengers at Stansted Airport, greatly angering disabled rights groups.[36] The airline argued that this provision was the responsibility of the airport authority stating that wheelchairs were provided by 80 of the 84 Ryanair destination airports[37] at that time. A court ruling in 2004 judged that the responsibility should be shared by the airline and the airport owners;[38] Ryanair responded by adding a surcharge of £0.50 to all its flight costs."
On 13 February 2006, Channel 4 broadcast a documentary as part of its Dispatches series, "Ryanair caught napping". Two undercover reporters obtained jobs as cabin crew based at Ryanair's operations at London Stansted Airport and secretly recorded the training programme, and cabin crew procedures. The documentary criticised Ryanair's training policies, security procedures, aircraft hygiene, and highlighted poor staff morale. It filmed Ryanair cabin crew sleeping on the job; using aftershave to cover the smell of vomit in the aisle rather than cleaning it up; ignoring warning alerts on the emergency slide; encouraging staff to falsify references for airport security passes; and asking staff not to recheck passengers' passports before they board flights. Staff in training were falsely told that any Boeing 737-200 (no longer in service with Ryanair) impact would result in the death of the passenger sitting in seat 1A, and that they should not pass this information on to the passenger. [5]
Ryanair denied the allegations and published its correspondence with Dispatches on its website.[49] It claims to have forwarded all 20 allegations to the UK and Irish aviation authorities, both of whom agreed that there was no substance to them. [6] It also alleged that the programme was misleading and that promotional materials, in particular a photograph of a stewardess sleeping, had been faked by Dispatches. [7] Much of the subsequent coverage of the programme in the media considered that the documentary was overblown and failed to make substantive claims against the airline, with some going so far as to label the attempted exposé as a vindication for Ryanair. [8] Following the documentary, Ryanair launched new services and a free flights offer.[
Ryanair has been described by the consumer magazine Holiday Which? as being the "worst offender" for adding extra charges to tickets [51]. These hidden charges include airport taxes, a fee to use airport check-in facilities, a charge for each piece of luggage checked in, and additional fees to pay by credit card or debit card. Ryanair was set a deadline of 31 January 2008 by the Office of Fair Trading to include these charges in headline prices, but failed to meet this deadline[52], even after an upgrade of its web site on 25 February 2008
So the answer to your question is erm a yes I guess!