Kind of unfair comparison. Katy could release a good album every year to better her chances. AND Aniston could only be nominated for one category while Katy is eligible for many Grammy categories.
Katy, of course. She's been nominated before.
On the other hand, movie awards are unpredictable, I mean Matthew McCoughaney, Sandra Bullock, Jonah Hill, Hugh Jackman...
I think Jen really blew her chances. She should've taken on some serious roles after "Friends" like "The Good Girl" (which is amazing) so she really has/had the potential. But her recent movies are just awful and its gonna take a hell of a climb before she wins an Oscar.