Another plus is that ODST is almost a Firefly reunion. Featuring the talents of Nathan Fillion, Adam Baldwin and Alan Tudyk for three of the main characters, including Fillion's own likeness in the game.
For fans of the series, especially the first game, they have a remake of the pistol from the original that is silenced. It also has a silenced SMG that can zoom in as well. I enjoyed the game, though it is really short but it includes the Firefight mode, which is Halo's answer to Gears of War 2's Horde mode; it also includes a disc with the Halo 3 multiplayer experience and all the downloadable maps including 3 exclusive ones. It really is worth checking out.
If you have an Xbox Live account feel free to add me. It's under "MacJase".