I'll save Laura because BB17 and cut Hannah because although I liked her, she's probably the weakest one out of the other three.
Hannah 'Miss Nigeria UK' Agboola

So this write-up is pretty hard for me because a) I didn't really mind Hannah, from the twenty or so episodes I watched of the mediocre BB18, and b) because I only watched twenty episodes of the mediocre BB18 so I think it's safe to say my knowledge on any housemate that isn't Sukhvinder is a little limited.
So instead, I'll just list everything about Hannah that I remember, such as that time she clocked Rebecca for chasing a guy that doesn't even want her (oop) or when she pulled the 'race card' after being labelled aggressive, I mean I would too if I was being crucified just for raising my voice once in a house where Kayleigh and Lotan openly threaten to assault people. Oh and that time she projectile vomited in a task where she was forced to eat a fermented egg (seriously, why are those tasks still a thing in 2017?). Anyway, I'm pretty sure we were all excited for Hannah at first, myself included, because this is TiBB and a sassy black woman to fawn over is a necessity to any series.
Let's not forget that magical time she overcame the odds and somehow made it to the final week, despite having Day 18 boot written all over her (funnily enough, Rebecca took that title) and her suddenly getting backdoored only meant she avoided the baying mob that no doubt would've jeered her off the stage, so all in all she pretty much won, no?
Oh, how I could I forget, buy Peace, Love and Harmony on iTunes or s/t.