Can everyone stop hating on Ketchup, please? If not for Ketchup's sake, than for people who ACTUALLY WANT TO TALK ABOUT THIS STUFF, rather than argue with the OP.
Anyway, I think Gaga is quite promising. I'm a fan of synth-pop and dance-pop, so I liked it. On the other hand, if I want synth-pop, I can just listen to The Human League. Her synth-pop isn't the most innovative, either, and for modern, non-'80s synth-pop, Girls Aloud have done a better job in that respect, and that's not even considering the '80s gods of synth-pop like Soft Cell and The Human League.
But she has talent for sure. I'd be interested in seeing more from her. She's making damn good pop music.
Britney is generally pop.
Although I guess some of her songs could be filed under the 'dance' genre...
I'd say she's close enough, and seeing as the pop thread has sunk, here's as good a place to discuss her as any. Her newer stuff (especially Blackout) is electronic enough to count, and Britney's strongest point was always dance stuff (not saying I don't love songs like Everytime, but you catch my drift).
I just bought Circus, and loved it. I think it's possibly here best yet. I never was keen on her early stuff (...Baby One More Time and Oops...) but since then, she's just become better and better.
The only song I was disappointed with was Womanizer. Was a bit too lacking in melody for me.