Justin Bieber.
.....God.
Lol, I'd like to say "I'm sure he's a perfectly decent person irl", but I'm really not sure that that's the case. Whenever I see pictures of him, he's just got this condescending "better-than-you" attitude that is completely misplaced.
All Bieber has going for him is a thyroid disorder. Big deal.
I'm not a fan of Lady Gaga's music, but at least she's a decent person. I saw some interview with her on TV, and she made perfectly intelligent, normal comments. She even seemed to have a sense of humor. On top of that, I guess her "act" is somewhat unique... a more modern more techno Madonna - that's kind of unique, so Lady Gaga's got a marketable "act", and I don't see her fading away soon.
So sure, Lady Gaga over "Lady Bieber".