Good Girl Gone Bad is overrated even though it has her best and most iconic song on it.
I use the singles (Bar the horrid "Shut Up And Drive") plus "Breaking Dishes" & "Lemme Get That".
Rated R is awesome. I used to dislike it, but gave it another chance after Loud was released. "Firebomb" - her best ballad -, "Russian Roulette", "Photographs", "G4L".. **** it, every single song (except "Stupid In Love") was great.
Loud is very good too. "Man Down", "Cheers" and "What's My Name?" are three of her best songs ever. "Skin" and "Complicated" are the most underrated songs there. "S&M" and "California King Bed" are my least favourites.