Team fortress 2 was the beginning of some of the best professionally created machinima or at least some of the most popular in a long while.
NC Soft is continuing their own series of machinima goodness with Issue 12: The Midnight Squad based on their popular MMO
City of Heroes. by the way I really like saying machinima. It sounds like something you would order at starbucks if you were feeling adventurous. One grande machinima please.