5. Team Fortress 2
https://www.youtube.com/watch?v=l62OY19rZ7k This one's cheating a bit, but it's hard not to mention every Team Fortress 2 'Meet The...' trailer when discussing Valve's amazing promotional videos. The series lasted over several years, with each introducing one of the nine distinct characters. Starting with 'Meet the Heavy', the series introduced every character percfectly, while showing off the realistic animations packed into a cartoony aesthetic.