The most popular machinima series is probably "Red Vs Blue", which was made with Halo, a popular game on the xbox.
Roosterteeth, the company who made the series, originally started with the concept of two teams, Red and Blue. They decided to make this story with Halo 1 on the xbox, for one reason or another. The advantages of Halo 1 can be seen here:-
Advantages:
-Multiplayer mode is a good way to make great machinima, you can use your buddies as actors and use one of the MANY different levels in the game as a set
-The ability to customise your armour colour makes it easier to identify different characters in your movie/series
-The ability to "head-bob", which basically means that if you look all the way down with your gun, and look up and down quickly, it gives the illusion that you are talking
-Vehicles are varied with a Warthog, Ghost, and the Scorpion tank
-A huge array of different guns
Disadvantages:
-Compared to most machinima's nowaday, the graphics seem outdated
-The crosshair in the middle of the screen cannot be removed, but only minimized by equipping a pistol as your weapon, the viewers must then try to ignore the crosshair and try their best to try and view the movie as it "is"
-Very restricted acting, there are no animations as such other than running, shooting, jumping, punching, entering vehicles, crouching, picking up a flag/skull, and reloading As you can see, there is not much you can do other than action movies at first glance, head bobbing is excluded from the animations list since it's more of a "glitch"
-No online multiplayer, so if you have a movie that requires a vast number of people, say around 12, then you will have to set up a lan, and that means getting extra tv's and more xbox's etc Also the cameraman needs a full tv screen to himself in order to record footage
-The interactivity of the levels is poor, nothing can be turned on or off, or moved, the only interacive pieces are things such as teleporters, and not all levels contain things such as that, although levels have many detailed attributes such as caves
Once Halo 2 came out, there was an uproar in the machinima community, Roosterteeth got straight to work at continuing their series Red Vs Blue, but using Halo 2 instead of Halo 1.
The graphics were considered good for the time as well, and the same advantages were kept but with a few more added in.
Advantages (same as above but with new features):
-Skull/Oddball glitch If the player has no weapons in his inventory OTHER than a plasma pistol, if he/she charges the pistol up by holding the fire button, and then walking over a flag/skull/bomb then the spartan will drop his weapon and the item he picked up and be left without a crosshair, this enables more immersiveness in peoples movies now since the distraction of a crosshair is now removed
-Even more weapons such as the sword, brute shot etc
-The ability to play online, now actors are easier to find since you can now meet them and play with them online in player created matches
-New maps
-Interactive levels, zanzibars gate, bridge etc
-The option to play as an Elite model as well as a spartan, more freedom for storylines, elites vs spartan wars etc
-The "glitch" to lower your weapon, it is not considered a proper glitch, since Bungie probably programmed this in on purpose to help Roosterteeth with their movies.The "glitch" is that if you deplete all your grenades and hold the grenade throwing trigger, you can lower you gun which makes dialogue scenes much more improved than holding a gun to someones face
-More vehicles
-Downloadable content to keep your movies fresh
Disadvantages:
-Same restrictions to animating the models other than the added lowering the gun trick
-Still only 16 players
-Everyone uses this game for machinima and so many people do not bother watching halo films due to an overdose of them
-Too many ideas have been done for this game, such as Elites vs Humans battle films, Humans destroying the opposing and opposite coloured team etc. Therefore it is very hard to come up with something that hasn't been done before
-Many issues of lag and juttering of online actors movement have been noticed, so if you are trying to film online and you are not the "connection host" then the actors will move very uncomfortably and juttering their movements, also the physics will not be smooth if you are not the connection host
So as you can see,Halo 1 and Halo 2 are basically the same, but Halo 2 is more adapted to the needs of machinima.
But since many people use this game as an engine for their machinima, your movie will probably go un-noticed as many people will call your series a "Red Vs Blue" Rip-off , or some related comment.
But if an original idea is made, or if a good quality editor is at your disposal, then using Halo 2 might be the best choice you ever make, and with so many sites dedicated to machinima with Halo 2, there's no reason not to get involved in the forums anyway.
Useful links:
www.redvsblue.com www.machinima.com www.halogrid.com (Temporarily shut down) www.snowglobepro.net www.machine-enema.com