WMG: Red Letter Media

Mike and Jay had a deal that if Jay could make Mike crack-up Jay would get his own segment.
After episode 44, Red Letter Media began to host a new segment titled Best of the Worst, which appears to be largely driven by Jay. In episode 45, we see Jay make Mike burst out laughing for perhaps the first time EVER. While episode 45 was released after the first episode of Best of the Worst, it's POSSIBLE it was filmed first, and thus Best of the Worst was born.

Recipe For Disaster is what Mr. Plinkett sees when he's off his drugs.

The timeline split at some point and created the two different Plinketts.
In fact, you don't even exist anymore.

Stoklasa's Plinkett is the grandfather of Evans' Plinkett.
Stoklasa!Plinkett's son killed himself when he realized how his son ended up like his father.

Plinkett's murderous attitude towards women is a result of him not liking things that are different.

Both Plinketts are the same person, and he suffers from borderline personality disorder.

Plinkett is possessed by a violently misogynistic demon, and the two repairmen are his unknowing disciples.
This would explain Plinkett's superhuman abilities as well as the repairmen's apparent compulsion for spending so much time at his house, reviewing movies.
Half in the Bag is Stoklasa!Plinkett's Start of Darkness
Think about how similar Mike from Half in the Bag and Stoklasa!Plinkett are. Looking and sounding similar is obvious due to Mike Stoklasa playing both, however the way Mike executes such jokes and the types of jokes used by him in general, is very similar to Plinkett. Also very similar is their hyper-analization of minute details. Take away Plinkett's homicidal tendencies, and really you could make a case that it's really just Mike's character/personality. So, Half in the Bag could as well be a origin story for Stoklasa!Plinkett dressed as a movie-review show.
Plinkett's cat did NOT in fact steal his merkins
The order was misplaced by Skymall, who then refused to take responsibility for their mistake.

Harry Plinkett's mother was somewhat of a sexual deviant.
Harry did say he was half-pig. Either this is just senility, or he really is half-pig. Not to mention that he threw his psychologist out of a window because he tried to talk about his mother, suggesting some serious Mommy Issues. Plinkett's mother was rather promiscuous, indulging in some rather questionable acts. Possibly as her job. This gave Plinkett some major issues when it came to sex and women, explaining why he's "a psychopath who butchers women." Depending on how squicky you want to get, he could have learned this from his mother.

Mr. Plinkett is woefully underendowed.
It would explain his violent hatred of women - it stems from having been laughed at so many times. It would also explain how he's physically able to fuck a cat.

One of the Star Wars: The Clone Wars writers have seen Red Letter Media.
In his Star Wars review, Mr Plinkett joked about how somebody like Jak Dex-Starr(or "This Asshole" as he puts it) would be able to use a lightsabre. In the Star Wars: The Clone Wars, Jedi/(turncoat) Pong Krell is both this asshole and the same species as Jak Dex-Starr. Maybe they thought it would be funny if they answered Mr Plinkett. For all we know, George Lucas himself saw it and wanted to troll Mr Plinkett. We still aren't sure whether he's the only person he's trolled.

The identities of the two VCR repairmen
Mike is Mikey from Recess grown up and 'Jay' is Hans Klopek from The Burbs living under witness protection having turned on his family.

Stoklasa!Plinkett got Evans!Plinkett to pretend to be him in Revenge Of Nadine.
In the trailer for the Indiana Jones and the Kingdom of the Crystal Skull review, the Plinketts are two different people who just happen to be very similar. However in Revenge of Nadine, the Plinkett that reviews movies note  is played by Rich Evans. It is possible that Stoklasa!Plinkett got Evans!Plinkett to pose as him while he left the country to avoid going to jail and/or getting attacked by Nadine by promising to fix his VCR and former home.