I might use the ram, dvdr, and the Extra HD's, but everything else is pretty much out-dated by today's standards. It really depends on what you want to use your computer for? Mine is still fine for what I do, light-gaming, surfing, watching DVD's, and stuff like that.
What are the specs on your comp and what do you want to do with it?
If you just looking to improve performance on a tight budget then upgrading might be the best route.