I don't think I can recommend Red vs. Blue enough. Unless you're not a fan of machinima, that is, or if you don't like Halo. It starts out with two teams of hilariously misfit soldiers fighting a civil war against each other in the middle of a box canyon and then... holy crap, the places it goes after that. Honestly, if I try to go into more detail, you'll get confused. This is a show that needs to be experienced. And to really love it, you need patience. The first season started out as a joke that wasn't supposed to go anywhere, but then it practically blew up in popularity overnight and they decided to just go with it The next few seasons are a bit haphazard as well, but still laugh out loud funny sometimes. It's not until you get to the fourth season that you start to realize the plot's building up to something big. The sixth season is where it all gets real. There's more action, more cohesiveness, more drama, and just more everything.
Seriously, if you make it that far, then you'll be left wondering how something so complex and brilliantly written could come from all that crap before. There's a reason it's the longest running episodic web series of all time.
The first 13 seasons are on Netflix, or you can watch all 16 seasons (and all five mini-series because those are important, too) on the Rooster Teeth website where it all began.
(Wow, that's long. I don't know if you can tell, but I really love this show.)