BB6: The box task, the speed-dating task (seriously, Kemal and Roberto's date in the loft is the most underrated moment, it was comedy gold), Makosi's secret mission, and the Room 101 task (simply because it was easy, it was relevant to the concept of Big Brother). Oh and the hospital task because it meant Craig got pregnant

and then Vanetha actually broke her ankle or something, silly bitch <3
BB7: the prison task, and I did like Big Brotherhood as a concept too. The two HMs left out were really good choices (Bonnie and Glyn). I can't remember too many others.
BB9: the chilis task
sorry, I'm terrible with remembering tasks