Fun. is celebrating its fourth week on top of the Billboard Hot 100 chart with the #1 smash hit "We Are Young."  According to Billboard, the song is now 2012's best-selling download, having moved 2.39 million copies, according to Nielsen Soundscan.  But the group says they're not #1 when it comes to actually having fun.

Asked by People magazine to name the most fun band, frontman Nate Ruess says, "Those LMFAO guys seem to have a good time.  Maybe they should take our name.  It suits them better because we're dorks."

Explaining how they come up with their unusual name in the first place, Nate tells People,"We were brainstorming names with a comedian friend, and we decided on Fun, but then a Swedish death metal band named Fun contacted us.  They were like, 'Change your name, so people know the difference.'  So we put a period on ours."

As for their unlikely hit "We Are Young," Nate says it was inspired by a rough evening he'd had.  "I just had a terrible night out where I drank way too much, and our bass player and my girlfriend had to take care of me," he explains.  "That inspired the verses."