Big Brother
Since "Big Brother 2", the UK series has opened with a twist. This has included having potential Housemates being voted upon by the public for one to enter the house ("Big Brother 2" &amp; Big Brother 13); public voting for least-favourite housemates, with the housemates choosing between two nominees to evict ("Big Brother 3"); first-night nominations ("Big Brother 4" &amp; Big Brother 13); suitcase nominations ("Big Brother 5"); Unlucky Housemate 13 ("Big Brother 6"); Big Brother Hood ("Big Brother 7"); an all-female house and a set of twins as contestants ("Big Brother 8"); a couple entering as housemates, who must hide their relationship ("Big Brother 9"); housemates having to earn housemate status ("Big Brother 10"); a mole entering the house with an impossible task ("Big Brother 11"); Pamela Anderson entering as a guest for 5 days (Big Brother 12); a professional actor posing as a housemate and a mother and daughter as contestants (Big Brother 14); one contestant gets a pass to the final (Big Brother 15); first night eviction (Big Brother 16); two houses with "the other house" featuring enemies from the main house housemates past (Big Brother 17); Jackie Stallone entering a house containing her son's ex-wife Brigitte Nielsen ("Celebrity Big Brother 3"); a "fake celebrity" (a civilian contestant pretending to be a celebrity) in a celebrity edition ("Celebrity Big Brother 4"); a visit from Jade Goody's family ("Celebrity Big Brother 5") and unlocked bedrooms allowing housemates to immediately claim beds with the last housemate becoming the Head of House ("Celebrity Big Brother 6").