Brian,
OK, so what's good? For my requirements, HAProxy is excellent. It
handled sticky sessions well, performs monitoring of each host, allows
dynamic adding/removing of servers, as well as maintenance modes.
It's very easy to install and configure. I'm using is as the backend
to apache that is acting as an SSL termination point. It's been very
high performing for us and I know a lot of big sites use it as well.
The only question I would have with it is handling of video, as we
only use it for typical web traffic, just high bandwidth stuff like
that.
Also, make sure any load balancer you have is redundant and has some
kind of failover, using something like pacemaker, heartbeat, etc...