I ended up getting 3 SSD drives recently. 1 for the OS and major software installs (Adobe products, FTP, anti-virus, etc.), 1 for game installs, and 1 for capturing game footage/scratchdisk/general usage. I also keep an external backup drive, as well as DropBox (for day to day stuff) and Carbonite for an overall, large scale, cloud backup.
Hopefully by separating the drives that way, any one won't be used too much, and if it is it won't affect the whole system.
I also learned that separating them this way helps in capturing game footage since you aren't running the OS, playing the game, streaming AND capturing footage all on the same disc and vying for resources.
Seems to be working well so far.