PSY's viral video "Gangnam Style" is now officially the most liked video of all time on YouTube.

Facebook/PSY

OOD DAY FOR:

A short jog
A new study finds that 30 minutes — and no longer — is the optimal amount of time you should exercise to lose weight. [Discovery News]

K-Pop
PSY's viral hit "Gangnam Style" becomes the most-liked video of all time on YouTube. [Gawker]

Heading west
According to a new report, four of America's five richest cities — San Jose, San Francisco, Seattle, and San Diego — are on the west coast. [Newser]

BAD DAY FOR:

Bursting decades-old bubbles
A British newspaper reveals that the iconic 1930s photo Lunch Atop A Skyscraper was actually staged for a publicity stunt. [The Daily What]

Multi-tasking
An armed gunman takes a hostage in a Pittsburgh office, but negotiations are hindered by his frequent and emotional real-time Facebook postings. [The Daily Dot]

Pulling a Boehner
Mitt Romney's face looks significantly darker during his appearance on Spanish-language news channel Univision, prompting accusations that he used bronzer to appeal to Latinos. [New York]

For more winners and losers see: Good day, bad day: September 20, 2012