Even though social media and Facebook fan page looks something totally new to marketers, the basic rule is the same as web site based online marketing. Such as contents first, engagement crucial, business later.
The Pepsi Refresh Project
http://www.youtube.com/watch?v=srY7Wkl2IbI&feature=player_embedded
Disney Thanks You: 100 Million Page Likes on Facebook
http://www.youtube.com/watch?v=bVQ4bskC6D8&feature=player_embedded
Coca Cola - Facebook Fan Page
http://www.youtube.com/watch?v=bfba3s7ThV4&feature=player_embedded
IKEA - Facebook showroom
http://www.youtube.com/watch?v=0TYy_3786bo&feature=player_embedded
Real life Facebook Like with Hyundai at the Autorai 2011
http://www.youtube.com/watch?v=bkQJHjUD6rE&feature=player_embedded
Schweppes profile app
http://www.youtube.com/watch?v=EEWNeV6TP2k&feature=player_embedded
Diesel Cam
http://www.youtube.com/watch?v=_P-zA90yI64&feature=player_embedded
Diesel Facebook Event
http://www.youtube.com/watch?v=9rJPIs0bN_o&feature=player_embedded
Summed up from http://www.slideshare.net/makiind/sns-1-7977391 (written in Korean)