I totally agree with your disappointing albums (sadly).
I also expected Unapologetic to be her best album so far after I heard Diamonds, but since you thought the same, you know how that ended. It doesn't even seem to fit the rest of the album, I just don't know. When I heard Unapologetic for the first time, I was extremely sad. Because of the snippets I could have anticipated that, but I liked them more then. Now I kinda accept it for what it is, nonetheless I wish this wouldn't have hit #1 because I fear that this inspires her to record more stuff like this which I don't want at all.
Red is definitely quite long and it would have been better if some songs weren't included, but I also really like some of the songs. The others are - as you already wrote - not bad, sadly they are just not exactly special.
I don't own Take The Crown, but I heard the full album (at least subconsciously) since nothing besides Candy caught my attention.
ORA... well, it's kinda similar to how I felt about Unapologetic. When I listened to the snippets I liked them, but when I heard the full album, I was disappointed. It's not cohesive and most of the tracks are just okay, while Fall In Love is just horrid (Hello, Hi, Goodbye also - thanks to the irritating noise in the background). I hope her US/second album is better since I absolutely like her voice. May I ask which songs are the ones you don't like? I'm just curious now