Critical Research Failure: During the Disneyland episode, George's mother claimed she rode the Matterhorn while pregnant with him, thinking the splash at the end was her water breaking. As the safety announcement played every 5 minutes during the line to the ride claims, pregnant women are heavily discouraged from riding the Matterhorn or any other rollercoaster, as it could easily lead to a miscarriage.
Benny's not one to take stuff like that seriously. Either that or she was being sarcastic.
And they likely didn't have such warnings back when she was excepting him.
The real research failure comes from the fact that George should be in his twenties as opposed to his late thirties/early forties.
Family-Unfriendly Aesop: The show gives the moral that sometimes bullying can get so bad, you have to run away from the situation. Carmen was called a whore at her first high school, due to her ex-boyfriend telling everyone that they had sex. George and Angie get the leader of the bullies suspended, and get the ex-boyfriend to tell the truth. However, the episode ends with Carmen still getting bullied, and George and Angie making the conclusion that Carmen can never get her reputation back, and that she must leave the school. Unfortunately, all of this is Truth in Television.
"Funny Aneurysm" Moment: An episode in the final season involves George being in the local neighborhood watch. While their goal is a little different (it involves finding a child molester who ends up being a woman) it is a little jarring considering the George Zimmerman incident. (A Hispanic man named George who was also involved in neighborhood watch).
Growing the Beard: The first season was rather forgettable, being little different then most family sitcoms with generic storylines and not-so-great humor. The second season, however, featured the inclusion of many story arcs, and a much more mature and better-received sense of humor.
Harsher in Hindsight: In one episode, George says that he's in favor of tighter border control, and now look what's happening with Arizona, be careful what you ask for!
Angie ends up taking too much charity work, and yells "They're deaf, George!" when he tries telling a group sitting in his kitchen table to leave. Her actress, Constance Marie, would have a deaf daughter on Switched at Birth.
Ho Yay: There's enough between Ernie and George that George ended having a worm-induced hallucination that he and Ernie were a gay couple. One moment that's worthy of mention is one time when George and Ernie are playing guitar and they get close and stare rather intently into each other's eyes.
The jokes about Fidel Castro in the show are now funny in hindsight since he died on November 25th, 2016!
Ricky was Max's delinquent friend who talked Max into a lot of stunts that damaged the Lopez house and drained their finances. But his childhood was pretty much the same as George's, maybe even worse, so George was willing to take him in.
Veronica was a spoiled brat who tested George's patience more than once. But her father was a manipulative conman who abandoned her, and returned again just to steal her trust fund money. Her mother was apparently dying for a while, and it's implied that her relatives were also poor role models for her, since her mother Claudia made George a trustee, and one of them later sued Veronica for her money, forcing her to live with the Lopez family.
Zack Powers is a subversion. He may have had a difficult childhood, but his embezzlement of company money, trashing the factory just to spite his father, and then trying to manipulate Carmen into having sex with him, and then running away to San Francisco completely shreds any sympathy.
Carmen hasn't had it very easy. George has often shown more favor to Max. Her best friend left her, one of her ex-boyfriends claimed to have slept with her to avoid being seen as a loser, resulting her in being bullied for "being a whore" so bad she was pulled out of school, another boyfriend was a lying slimeball who just wanted to screw her, and manipulated her into running away to San Francisco, and later dumped her. Her next boyfriend was at first embarrassed to be seen with her, and then cheated on her. The girl has been through a lot, and you hope she can achieve more in college. That being said, many of her troubles strem from her being a Horrible Judge of Character, a complete Drama Queen, or both. She even tried playing the sympathy card in order to do whatever she wanted after she returned home.
Les Yay: In one episode, Veronica mentions that she was hit on by two store managers.... and that one of them was a girl. Max, who was with her at the time, comments, "It was awesome."
Rewatch Bonus: In the episodes leading up to "George Helps Ernie See The Cellulight" where Ernie gains weight and almost gets fired, he is noticeably heavier. George even comments on it in the episode "The Kidney Stays in the Picture." He looked like he was wearing a fat suit, though.
Strawman Has a Point: Hoo boy does this fit George. His cynicism and vitriol in various situations is often condemned but usually validated.
The best example of this would probably be when Benny moves into the house temporarily. George warns Angie against allowing it and is proven right when Benny's constant presence and refusal to be responsible so she can move out eventually cause even Angie to want her gone. In spite of this George is shown as in the wrong for wanting the throw her out despite his mother going out of her way to demean and humiliate him while receiving no support from even his wife.
Uncanny Valley: The flashbacks to George's childhood, which show George's adult head pasted on his childhood body. Extreme Narm ensues when said scenes are intended to be serious, such as the flashbacks that led up to George's abandonment or Benny's neglectful parenting. Needless to say, these scenes can't be taken seriously with the adult head/child body combo.
During Benny's trial, George brought in Benny's mother to the stand and try and make Benny sympathetic to the jurors. While on the stand, she proceed to mock Benny and shows how bad a mother she was to Benny. This was done to make Benny seem like a Jerkass Woobie at the most since how bad she grew up in a broken home and being a single mother. The problem was that Benny was just as bad at raising George. Being emotional and physically abusive to him, being neglectful of his feelings, disregarding his dyslexia, unsupportive of his goals, and lying to him constantly. And as an adult she still a Jerkass to him and his family. She is the reason he has so many repressed memories and a demon parade. It's pretty hard to sympathize with her.
Benny falls into this a lot. In one episode, George completely remodels her bathroom, free of charge (and even throws in some custom stuff). When she complains about this and he rightfully calls her out for being ungrateful, she launches into a rant about all the bad things that happened in her life. The logic gap from being angry at people in your past and never saying thank you to your son is pretty blatant.
Vindicated by History: Onetime George bought two tickets for him and Angie to Cuba, which will be for a future date when Castro is dead or Angie's Father wouldn't care. Flash forward to December of 2014, Castro stepped down for his brother to take over and relations between the United States and Cuba are normalizing including less travel restrictions.
Even more so now that Fidel Castro has died in November 2016.
The Weird Al Effect: Those familiar with the show are more apt to recognize "Low Rider" by War as "the George Lopez theme song".
The Woobie: Ernie can fall under this. He's had terrible luck with women, and one that was even chubbier than him ran out on what was supposed to be their first date.