For youtube on FiOS specifically, you can change your dns servers away from verizon's and it'll start going a lot faster. I can't find the link right now, but u

For youtube on FiOS specifically, you can change your dns servers away from verizon's and it'll start going a lot faster. I can't find the link right now, but using their dns servers points you to cdn/caching nodes hosted by verizon, which are generally massively over saturated. If you switch to google's public dns or another public dns service (or run your own resolver if you're a masochist like me) you usually end up hitting edge nodes that aren't completely saturated and you get far far better speeds.