This information was taken from http://www.ukfilmcouncil.org.uk/media/pdf/2/p/2009.pdf

I checked the ukfilmcouncil to find out which one of the three genres (romantic comedy, horror, thriller) is the most popular and which genre has made the most money. From the picture above you can see that the comedy genre is the most popular with people with 140 releases grossing £222.4 million at UK and Republic Of Ireland box office. One of the top performing titles of 2008 was Sex and the City which is a romantic comedy and that film alone grossed £26.43 million in the UK (http://www.ukfilmcouncil.org.uk/media/pdf/k/r/UK_box_office_report_2008_22_1_09.pdf). The next most popular genre is horror with 28 releases which grossed £23.4 million at box office. The top performing title for this genre was Saw V which grossed £5,617,718. (http://www.ukfilmcouncil.org.uk/14952). Finally the least popular genre from all three is the thriller genre. The amount of thriller releases was the same as horror but unfortunately it did not gross as much at box office as horror. The thriller genre grossed £21.2 million at UK and Republic Of Ireland box office 2008. This figure is very close the amount the horror genre grossed so I would say that it the horror genre is slightly more popular than the thriller. The top performing title for thriller was No Country for Old Men which grossed £1,257,183. (http://www.ukfilmcouncil.org.uk/13588)