^ Damn, that post makes me feel old.
For many years it was Rooster Teeth's flagship juggernaut show.
It began life in 2003 as a goofy Halo machinima series, then as the seasons went by the production value increased and it became more plot heavy,
until eventually they were able to switch to fully 3D animated.
This music video is a good summary of the action elements, dramatic elements, and lighter elements.
The switching between clips from every season (at the time this was made) also makes for a slightly amusing affect for seeing the quality difference between the machinima era and the animated era.
For the newer crowd/generation, Rooster Teeth is now often best known for making RWBY.
But I fondly remember when Red VS Blue was considered one of the hottest webshows of the late 00's / early 10's internet.
I still own the remastered Blood Gulch Chronicles (seasons 1-5) DVD boxset.