I had the same problem at home, sucky internet.
My netflix would buffer, youtube was unwatchable, anything that involved wifi was very slow.
My wireless network at home consisted of a Airport Extreme Gen 3, Airport Express Gen 2 and a wifi extender upstairs.
After some internet searching and a genius talk at a local Apple store, I learned that wifi devices do not last a lifetime.
I bought a new Airport Extreme at BestBuy ( I asked them to match a Educational discount on the Apple Store site and they did. ) I swaped out my 8 year old router at Time Warner with a new one. I disconnected the wifi extender. Now everything works great and no buffering.
It may be the age of your equipment. I swaped out my stuff for new and all is great.
It worked for me.