Just do something on sports, its the best way to go. Add some sweet theme music, something to get the crowd going, then just use highlights of like one real good player, such as Kobe Bryant, you can find some sick dunks and shots that he has made through out his career. There are many videos like these, on google video, seach kobe Bryant, and you will find tons and tons under "google Video"...Just use them as ideas, and make your own. If your into sports, some of these videos really get you going. The main thing is the music though, if you put the wrong song the whole video could be a disaster.....
This one is kinda weak..but its an exmaple...you need to get some fast music, and some nice crossovers and dunks, it would be a sickkk video man...