Ben Wheatley directed this film, I haven't seen any of his other two film but I would really like to. In saying that the best thing for me was the script and story which was written by the two actors (Alice Lowe and Steve Oram), their deadpan delivery and the gory, early Peter Jackson-like (think Braindead and Bad Taste) killing scenes. Sightseers is a humourous tale of casual romantic murdering, as the Chris and Tina (played by Alice and Steve) traverse the lush English countryside in a caravan. At the beginning the film shows an oppressive relationship between Tina and her mother, akin to that in the play, The Beauty Queen of Leenane. She is whisked away by ginger-bearded Chris, to her mother's dismay and along the way as well as killing innocent people as if they were getting a coffee and a biscuit at a tea-room, they partake in numerous cheesy tourist activities. I didn't like the cinematography so much. There were a couple of obscure angles which seemed like they would have had their home back in Shaun of the Dead or Hot Fuzz, but weren't frequent enough here to be a deliberate aesthetic. It's okay though, 'cause the acting was great, the script was great, it was funny, and frustrating and the costuming was satisfyingly horrific (think acid-wash jeggings). I liked this heaps.
(Another thing: Sightseers was preceded by a short film called 'Bear', made by Nash Edgerton, which was just as funny/frightening/unfortunate).