Rihanna claims almost none of her first two albums. I don't think there are any receipts of that, but from interviews you get that vibe. Plus it's kind of common sense in general that she would.
She also shades Rated R a lot lately. She always claims there were aspects to that era she wasn't in support of, but she never goes into specifics. I don't think she likes Only Girl (In the World) that much, either.
Nicki seems really embarrassed by her mixtapes for some reason, but I don't know if she dislikes/hates them for a fact. I do know she absolutely despises Your Love, though.