I can't be certain how long it has been like this, but youtube is all but useless on an uber fast Verizon FIOS connection now.  It used to be fast, but lately, you literally can't watch anything, not even a 240p video as it just sits there buffering indefinitely.  This happens on any computer, any router connection, any OS.  I can literally pull up a youtube video faster on my cell phone over a 3G connection than I can on my FIOS connection.

Cypher sent me this and it works.
http://forums.anandtech.com/showthread.php?t=2306808

For a Windows PC, just enter the following command into a CMD prompt (might need to make sure the CMD prompt is run as Administrator)

netsh advfirewall firewall add rule name="A_FIXYOUTUBE" dir=in action=block remoteip=173.194.55.0/24,206.111.0.0/16 enable=yes

If you are on linux or want to do this on your DD-WRT router (might even work on Mac OS X):
iptables -A INPUT -s 173.194.55.0/24 -j DROP
iptables -A INPUT -s 206.111.0.0/16 -j DROP

On the windows-side ( win7 or win8 ), to see the firewall you  just created, go to start > firewall > go to the "advanced settings" > inbound rules > you should see the "A_FIXYOUTUBE" rule at the very top of the list (thus the reason for putting A in front).  Delete it or modify it if you find it causes any issues.

Now let's just hope Verizon and Google can work out a fix.  There are tons of threads out there on this issue and the latest from Verizon is they are aware of the issue but don't have a fix yet.

I set up the firewall rules in pFsense.  I haven't really noticed any difference.  I'll keep them in for a while and see what how it is over the course of time.