Oasis hasn't sounded like Oasis since "Be Here Now" really. I keep buying cause I'm a fan, and I do like some of the stuff. But I've always hoped they would return to the sound of the first three albums.
Then you have those bands, that at least I think, sound better after they lose their lead singer. Genesis is one of those. After Peter Gabriel left and Phil Collins took over the band had a better sound and more success. And yes I like Genesis, and you can fuck off if you don't like that.
I also thought Van Halen sounded better with Sammy Haggar then with David Lee Roth, but I know I am in the minority with that one. Same with AC/DC.