Quake may be the historical parent of machinima, but Halo arguably popularized and assisted with the creation of one of the first (maybe the first) large and active machinima communities. Machinima historians (they exist, right?) can probably chart the maturation of machinima filmaking using the Halo series as a recurring example. As each game was released, the complexity of the graphics and physics engines combined with the inclusion of machinima friendly video capturing tools increased the accessibility and utility of Halo as a machinima platform.
The release of Halo 3 brings about a new wave of machinima with an increased technical capacity (more prims) that affords the machinima producer more expressive capabilities as well as a richer visual language. The following videos are among the most popular at a major Halo 3 machinima site.
http://gameroom.mlgpro.com/view/rhojIAED55g.html (Barrel)
http://gameroom.mlgpro.com/view/awsulpP0lFYltU.html (Grenade)
http://gameroom.mlgpro.com/view/2QekrQvfhsalsQ8k.html (Vehicle)
Currently, the videos are fairly “primitive” in their plot/story/content. The vast majority of Halo 3 videos record crazy kill shots or break downs in the game engine. This was the case with the previous Halo releases. Stories will come with time. However, the level of “professionalism” of the cuts, camera work, titling, voice overs, etc are better than previous generations of Halo machinima. I’ll venture a guess and say that the audience is getting better at producing films (largely because they’ve had a chance to consume so many and reflect on the good and bad qualities of the genre) and the technology is enabling better access to the video footage.
Hopefully that was a good enough attempt at intellectual muster to justify three cool Halo videos. Note: It does not require much muster to justify said videos given the extreme nature of their coolness.