Steve Ballmer, CEO of Microsoft, is known for his exuberant personality, which can seem a bit over the top at times. These videos demonstrate what we mean.

1) The most widely circulated video is one titled “Steve Ballmer Going Crazy”—and it has more than 5 million views. The video shows Ballmer at the company’s 25th Anniversary in September 2000. When he is announced to come on stage, he starts running around, doing what he calls a “monkey dance” and shouting “give it up for me!” When he finally calms down, barely able to speak between gasps of air, he manages to shout four words: “I. Love. This. Company!”

2) In this clip, Ballmer is at a developer’s conference and starts chanting “developers, developers, developers” while clapping, and the audience joins in. It’s hard to not stare at the perspiration drenching from his shirt as he chants enthusiastically. The “developer chant” has been chopped and screwed into remixes and music videos, often mashed together with some of his other crazy moments.

3) Clearly, Steve Ballmer is crazy about developers. In this earlier conference during the MIX 2008 event, where he was engaging in a question-and-answer session with Guy Kawasaki, he was asked by a member of the audience to do a “web developers” chant, similar to one he did eight years prior. He says, “I’ve been in PR mode the whole time, and you want to hear web developers, web developers, web developers!”

4) Ballmer gives it up for advertisers in this clip. “I used to tell our people, Microsoft was about one thing…Windows, Windows, Windows, baby! We had a conference of developers together, four or five years ago, and I was all pumped up, we had our new dot net stuff coming; I was just a little bit emotional on stage… This is in a sense what the bedrock of Microsoft had been; now it’s advertisers; but the bedrock of Microsoft had been getting after developers to extend our platform. So as I think, ‘it’s all about developers, developers, developers,’ but not anymore, baby! It’s advertisers, advertisers, advertisers!”

5) It’s 1985 and Ballmer is selling Windows 1.0 with the enthusiasm of a top car salesman. The video, which has over 2 million views, shows Ballmer speaking a mile a minute about the new technology. He’s happy to announce features that seem so obvious today, like a notepad and a clock. The platform was just $99, and you needed to order directly from the company.

6) Here he is, selling again! “How much do you want this totally new Windows?” he shouts. “Wait just one minute before you answer! Watch while I make Windows XP the center of my home! All my pictures, all my music, all my videos, all in one place!” Somehow, he manages, to finish the commercial without bursting a vein on his forehead.

7) This video wouldn’t have made the cut, if it wasn’t for the fact that he jumps from shouting about blogging to calmly answering the interviewer’s question.

8) When asked what his reaction was when Steve Jobs pulled out the iPhone, he replies, “Five-hundred dollars, fully subsidized, with a plan? I said ‘that’s the most expensive phone in the world, and it doesn’t appeal to business customers because it doesn’t have a keyboard.’” Ballmer laughs at Apple for creating the most expensive phone on the market.

9) At the Hungarian University of Economy, one student stands up and shouts some words through a barely audible accent, mentioning to “give back to taxpayers” before he begins launching eggs at Ballmer. Ballmer ducks around, completely thrown off by the act. When the man is removed from the lecture, Ballmer says, “It was a friendly disruption. I lost my train of thought.”

10) He’s not only laughing at the iPhone. When asked about Google’s Chrome OS, he laughs after being lost for words, saying “Who knows what this thing is? They already announced an operating system, I don’t know if they can’t make up their mind or what the problem is [at Google]. But the last time I checked, you don’t need two operating systems.”

11) This video is self-explanatory. He IS a PC.