I need to replace the Hard Drive on my MacBook Pro 15" because I've been having some issues that usually indicate the HD might be failing, but I need advice to make the best choice when I get the new one. My mac's specs are: 2.8 GHz Intel Core 2 Duo, 4 GB RAM and it is the 5,3 model from mid 2009. It originally comes with a TOSHIBA MK5055GSXF of 500GB in capacity, so I need at least that much space and SSD is out of the question because of price. I've been looking at the following options: 750GB WD Scorpio Black 7200RPM 2.5" SATA HD 16MB Cache 640GB Samsung Spinpoint 7200RPM 2.5" SATA HD 8MB Cache 500GB Seagate Momentus XT 2.5" SATA 7200RPM/SSD Hybrid Drive 1.0TB Samsung Spinpoint 5400RPM 2.5" SATA HD 12.5mm with 8MB Cache Which one would you get? Any other brands/models I should look into?