Celebrate Katy's 31st birthday with some of her best videos.
2. Hot N Cold
This video is amazing for obvious reasons..and also proves that Katy did crazy girlfriend long before Taylor.
3. The One That Got Away
Another sad video about love lost, "The One That Got Away" is more mini-movie than music video...and one that always manages to make me cry.
4. California Gurls
No list would be complete without Katy's fun, colourful and incredibly sweet video for "California Gurls", which marked the debut of Katy's infamous whipped cream bra.
Because...How can 1 billion views be wrong?