Worth Getting a New Hard Drive?

[PcGamingRig]

Hi

I am upgrading my system to an i7 core and DDR3 and I was wondering whether it is actually worth getting a new hard drive...

The one I have at the moment I transferred over from my families Dell PC 3 years ago lol, I am not even sure what the make of it is.

Is it worth getting an SSD for my upgrade? What type of improvement do you get in gaming and other aspects?

Thanks.

 

[PcGamingRig]

My current one is 550GB btw, not sure about the speed of it.