It honestly doesn't really matter. But Lady Gaga actually sings, opposed to Ke$ha. They each have different approaches to performing, singing and just expressing themselves in general. Its retarded that you guys have to fight or compare her to people.

Its obvious that it was a stunt.
At the end of the day, both of the girls are on top with their hits.
They're only famous because we keep talking about them. If you truly disliked them, you wouldn't be talking about them whatsoever :p