As a person not living in the UK, the list will be so limited.
CBB1: No one
CBB2: No one
CBB3: Brigitte Nielsen, Jackie Stallone
CBB4: Dennis Rodman, Pete Burns
CBB5: Jade Goody (just because she was on BB), Jo O'Meara, Jermaine Jackson
CBB6: Coolio, LaToya Jackson, Mutya Buena, Verne Troyer
CBB7: Ivana Trump, Sisqo, Stephen Baldwin
CBB8: Jedward, Kerry Katona, Tara Reid
CBB9: Frankie Cocozza
CBB10: The Situation
CBB11: Rylan, Spiedi
CBB12: Dustin Diamond
CBB13: Evander Holyfield
CBB14: Gary Busey, Stephanie Pratt
CBB15: Katie Price, Perez Hilton
CBB16: Daniel Baldwin, Farrah Abraham, Fatman Scoop, Janice Dickinson, Tila Tequila
CBB17: Angie Bowie, Jonathan Cheban, Tiffany Pollard
CBB18: Frankie Grande
CBB19: Ray J (besides the All Stars)
CBB20: Amelia Lily, Brandi Glanville, Sarah Harding, Trisha Paytas
CBB21: Courtney Act, Malika Haqq, Jonny Mitchell (because of LI), Shane Lynch
CBB22: Dan Osborne, Kirstie Alley, Natalie Nunn, Rodrigo Alves
I genuinely have heard of some of these people before CBB while some on here I've only heard of because their names have constantly been thrown around as speculation for a long time on prior series before they actually came on the show.