Mirren, excellent though she is, didn't win the Oscar, the Queen did. The American voters on the academy were voting for Her Maj rather than the actress I feel. Mirren has said this herself.
I laughed at the Dead Ringers sketch where Dame Judi said "we've all done Queens, love." Very true. It sometimes seems that a British actress can don a crown and get an automatic nomination, whereas if they play other roles they get far less kudos.
Paltrow's Oscar was the least deserving in recent years. Actors often win not because of the merit of their work, but for the role they are playing.
I really feel that Helena Bonham Carter's amazingly subtle, sensual, and thoughtful performance in The Wings of the Dove absolutely deserved the Oscar in 1998 (1997 Oscars of course). She won all those critics prizes, was the odRAB on favourite to win, then Helen Hunt won (because she was American). Its very sad that it is HBC's only Oscar Nom, as she also deserved noRAB for Fight Club and HowarRAB End.