These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Epileptic Trees: Church took over the Meta and used Wyoming's time control ability to escape the "Ehmp"? Epsilon is in Caboose? For a web series created by a bunch of self-proclaimed drunk guys, Red vs. Blue seems to get a lot of plot analysis.
Burnie even addresses this by saying that people sometimes get the plot exactly right in the forums.
Although Word of God is that the above-mentioned bit isn't one of those times.
Evil Is Cool: The bad guys of "Blood Gulch" weren't exactly uncool, but Meta takes this trope Up to Eleven as the most badass villain in the entire series.
Fanon: Among other things, York and Maine's real names (James and Theodore, respectively,) and that Washington was a survivor of Reach.
"Funny Aneurysm" Moment: After Caboose leaves Rat's Nest, the blue in charge says that things are finally looking up for the team. The next time we see the Blue Base of Rat's Nest, all of the Blues have been killed by the Meta.
What Could Have Been: The commentary for Reconstruction reveals that an unused alternate scene (meant to be played behind the monologue of the final episode) was to show the Meta using Omega as a projectile, causing one Freelancer security agent to kill another, then leave the other vulnerable.
Badass Decay: The Meta, who was the most dangerous thing around in Reconstruction now reduced to being Washington's lackey. Justified in Season 8 with the reveal that the "emp" in Season 6 killed the Artificial Intelligence units in his armor to make him able to run his equipment, rendering him weaker than he is used to being. Then he takes on Tex alongside Wash and wins, reversing this entirely.
Epileptic Trees: C.T. has created many, mostly in regards to who it was that ordered him to go to Sandtrap. The fact that Washington seems to know him (or rather, her) in Revelation and said that it was "impossible" for her to be there only adds to them.
Delta: I believe that Agent Washington's sanity is well within acceptable deviations, for now.
He's Just Hiding: When Wash shot Donut, theories involving holograms sprang forth from the discussion boards on the site. (These were quickly Jossed.)
Moral Event Horizon: Washington shooting Lopez and Donut. Neither had posed anything near a threat to him, and he just shot them. And while Lopez is a robot, Washington probably didn't know that. And even if he did... For Donut, there was no excuse. In fact, he killed the two characters who had nothing to do with his incarceration! Subverted in Season 8 with the revelation that he just put a possible threat into recovery mode, though none of the other characters present at the time knew this ( he would also later save Donut from an attacking Tex robot duplicate, and say "we're done here"). In the case of Lopez, on the other hand, he did say he had made backups of himself in the case that he were killed.
They Wasted a Perfectly Good Plot: Early in the season there appears to be a Running Gag where Grif and Simmons are effectively swapping roles. Simmons is growing more frustrated by Sarge's craziness while Grif is actually be more helpful, to the point where he and Sarge are almost talking on more pleasant terms. This all gets dropped the moment that Sarge and Grif head to Sandtrap, leaving Simmons behind at Valhalla.
Season 8: Revelation
Badass Decay: While the previous season dropped the Meta's cred, this one digs it even deeper and drags Washington with him, as the pair of them act like a pair of 80's cartoon villains unable to puzzle out simple problems that Doc solves without even realising, leaving Washington to gripe like a retiree at a supermarket. But then the finale rolls around...
During the showdown in Episode 10. The score can be found here. The link contains spoilers.
Also, the inspirational tune from Sarge's "Do you ever wonder why we're here?" Speech in episode 18.
The utterly epic battle in Episode 19 is accompanied by equally epic music. It's also in the credits and episode 20 and is in fact called "Red Versus Blue."
"Funny Aneurysm" Moment: Tucker tells Tex and Church not to come and ask the other Blues or the Reds for help if they die again, as they usually do, when they go to arctic Freelancer Base. A couple episodes later, The Meta stabs a two-foot spike into Tex's helmet.
Narm: Shannon Mccormick's delivery of this line is... kinda cheesy.
Washington: Get them, Meta. Get them!
Nightmare Retardant: Before he cracked wise to his handler, lost most of his enhanced abilities, and carted around medics embedded in giant slabs of stone, the Meta was actually pretty terrifying. He does become a badass once again when he fights Tex with no AI or powers. He gets back into Nightmare Fuel when he gets his powers recharged. As shown by Season 9, however, this isn't exactly unusual for him pre-insanity, as he and Wash were actually good friends.
They Changed It, Now It Sucks: This has been the reaction of part of the fan base towards the fancy new CGI moments. Many of the older viewers enjoyed Red vs. Blue for its use of a limited toolset (i.e. "pure" machinima) to tell stories, while others believe that the new focus on action detracts from the series' classic humor.
Caboose. When you stop to think about it, after Reconstruction, he was alone. He needed someone in his life to look up to, but without his "best friend," he was the only Blue in Valhalla. And then, by the end of this season, Cabooses loses his closest friend all over again.