There are two types of people in this world, those who know who HK47 is and unfortunately, those that do not. If you haven't played Star Wars: Knights of the Old Republic, you are missing out on fantastic gaming. Yes there is in fact a sequel as well.
If you are looking to start, here are some mods for the first KotOR. This will improve the visuals to a degree.
Here are some fun conversations you can expect to have with the loveable HK47.