the answer is more than obvious

The power of Since U Been Gone.

This post explains it quite nicely, though I wish Gaga were in the center.

Have you seen Gaga's page? They barely even have anything on there for her. Only "Poker Face", "Bad Romance", and "Paparazzi" for songs and none of her albums.

The ranks are based on Decade-End, All-Time, and Year-End accolades.

Sis legend x stands on her own she doesnt need a trinity tha star, ha voice alone overshadows half of these names on this list

Britney Spears, Lady Gaga, Beyoncé.

I lol'd at the Lana, Adele, Marina trio. They would clash SO bad! Although i would love to see how that turned out. Gaga + Bey + Brit would dominate every single chart. Even Rap.

They know how to sell singles don't they?

Gaga, Rih and Katy make more sense as a trio, they're like the current top pop girls

Gaga, Britney, and Beyonce

Gaga, Bey and Brit are easily the strongest. Overall appealing, commercial and fascinating to read about. Who else?

The answer is obvious, but they're not similar like the rest of the groups. The rest of the groups all have a common ground (generic pop, breakups, pop-rock, Disney), they don't.

I voted for Bey, Gaga and Brit, of course.
Although Bey should be replaced. By anybody really.

My favorite is the option where is Avril, cause I love pop rock... but I hate Kelly Clarkson... so my perfect trio would be:

Avril, Britney and Rihanna