well madonna has been around longer so the answer is pretty clear.
But Gaga has the same ambition and three times the musical talent to overtake her. Not to mention she's more edgy and interesting.
And for all those who say Madonna has done everything that Gaga is doing. That sure is a bunch of crap. Madonna borrowed from many artists from the past. Back in the 80's & 90's she was seen as a copy machine.
Just the fact that she's being compared to madonna and doing bigger things than her this early in her career only proves Gaga will get bigger and stronger. It took madonna 7 years into her career to leave the bubble gum pop behind and start getting into deep stuff.
Let's see what Gaga has in store for us in the future.
Madonna. End of story. Gaga is on her way up there though. She has very obsessive, devoted fans (and the talent to back it up). I happen to be a fan now also. I just don't refer to myself as a little monster...