What are they?

Bad Romance
Wrecking Ball
E.T.
Single Ladies
Telephone

Beyoncé and Gaga slaying.

E.T. tho

Single Ladies
Telephone
Bad Romance
We Found Love
Wrecking Ball

In terms of pop girls:
Toxic
Crazy In Love
Bad Romance
Single Ladies
Wrecking Ball

Third millennium?

2000 was the new millennium...isn't a millennium every 1,000 years?

In terms of pop girls:

Toxic
Umbrella
Hung Up
Single Ladies
Wrecking Ball

We Found Love
Bad Romance

Toxic
Single Ladies
Wrecking Ball

Honestly can't think of anymore.

Single Ladies
Bad Romance
Wrecking Ball
We Found Love
Toxic

Bad Romance
Telephone
Wrecking Ball
Single Ladies

Can't think of anymore.

Oops : the bodysuit, the choreo, the hairdo, the little acting, everything about it
Bad Romance : it basically helped reintroduce quirkiness to pop
Single Ladies : one of the most iconic choreo-based videos ever made
Beautiful : ahead of its time, controversial, opened doors for gay imagery, still imitated today

The 5th one is between Umbrella, Crazy In Love and Wrecking Ball I think

Wasn't oops released in 2000?

Toxic
Single Ladies
Bad Romance
Telephone
Wrecking Ball

Toxic, Single Ladies and Wrecking Ball are the only for sure answers

Death @ anyone including Telephone, you can't be serious