Partioning my 1.5 tb hd

This is entirely a matter of personal taste. Some experts go with one partition, some with two or three.

My personal solution is two. The first one is for the OS only, and the other for all data, game saves, music files, and whatnot. The OS partition is backup up as a complete image; the data partition has a normal full / incremental backup cycle.

My main reason is that I am able to restore my OS to a known state at any time without losing any of my files.