That all depends on what you want it for, how reliable you want it to be and how much storage you need.
Personally, in a laptop I'd go for an SSD, but your trade off is they cost a lot more money and if a chip gets fried, there's no recovering your data. That's not to say that would happen, just want to inform you of the risk.
Otherwise, if you don't really care about performance boost, then just get any 2.5" internal hard drive that takes your fancy really. They're all much the same.