I would make 3 partitions -- that's how I would do it, if there is no SSD drive.
HDD - partition 1 70GB W7 + all the programs + page file -- If u game increase the size.
HDD - partition 2 @50GB - photos, project and other files up to 5MB + Document folder
HDD - partition 3 @170GB - music, videos and other files.
This is how do u move the Documents off of the system drive, so if C:\ gets corrupted, u don't loose the data : )
http://www.tweakhound.com/windows7/tweaking/5.html