I haven't seen that many. A few years ago I stumbled upon Imaginary Bitches, which was okay. Dr. Horrible's Sing-Along Blog, which is amazing. But I consider the latter a made-for-internet movie (although it's consensually been considered a TV show... whatever).
I found The Guild on Netflix, and since then I've been watching it. Personally, I like it. It gets better and better with each season.
But like I stated, I haven't seen that many. So I'm not that great of a judge. The real question is, what's your favorite made-for-internet TV show?
(http://www.thewaitingroom.org/images/avgn.jpg)
The Spoony Experiment, and most of Channel Awesome.