Considerations for New Hard Disk

I need to purchase a new hard disk, but it's been a long time since I've shopped for those. I was hoping someone could provide some guidance regarding what to look for nowadays. First, my system is a MacBook Pro5.5, purchased in late '09, and I want to make sure I get the right size. I assume it's a 3.5" drive, but in looking at my System Information file, it doesn't appear to identify that. Second, I'm thinking I want to get a 1TB drive, but what are the considerations I should look at in finding the best value. Price is important, of course, but it's not the only thing. Thanks in advance for any guidance.

Desktops have 3.5" drives and notebooks like your MBP use 2.5" drives. Your model has SATA II with a speed of 3GB/s and that is what you need to look for. Western Digital are pretty reliable, also Hitachi ad Toshiba, with Seagate becoming less popular of late.

Price and size is up to you so shop around. As your MBP is now four to five years old consider purchasing a SATA cable as these often become brittle through heat and fracture when being handled.