I have a Macbook laptop I bought 5 years ago and it's still going strong. It still runs as fast and smoothly as day 1. I am a MAC from PC convert and i'm never going back. I'm not an apple fan boy, but you gotta hand it to them their stuff works and works well. Laptop PC's last about 2 years until they break down(my own experience/observation with others). Macs take a while to get used to but its pretty simple. If you do decide to go with mac, get a solid state drive macbook, they're super fast. Almost every single time a computer has a problem it has to do with moving parts(my own experience).
My goal is to have my laptop for 10 years or more. So far its going for 6 years here soon and it looks like its going to do fine =).