Creator's Pet: "'Cute' Kid" videos generally tend to be this. They're almost guaranteed to take home the first place prize in every episode one appears in, despite most of the at home audience being very vocal about disliking them. Most of them aren't even all that funny, to begin with. The worst example has to be the clip 'the crying game' which features a kid throwing a tantrum and following the camera around and immediately throwing the tantrum again once he's back on camera for attention. Despite most of the home audience loathing this video for reasonsyou'd expect, it ultimately ended up winning a season finale grand prize. Maybe the studio audience just felt bad for the kids parents...
Hilarious in Hindsight: During the Grand Prize Disney World episode from 2007, Tom Bergeron joked that his dog was so smart that he had his own blog. This was several years before Disney Channel debuted a show with that very premise.
Nausea Fuel: The Bergeron-era segments "The Naughty Files" and "A Moment of Ewwwww!" specifically showcase grosser clips than the producers were allowed to show before. Snot and vomit gags (usually via babies) have popped up elsewhere as well.
One $10,000 winner featured a decapitated fish head on a plate in a sushi restaurant. It was still moving.
Nightmare Fuel: The Vin Di Bona Productions Vanity Plate at the end of the show, up until 2008, had a synth jingle that tried to sound cheerful but ended up sounding creepy. It was thankfully redone in 2008; some may find it a bit creepy, referring to the low pitched version, but it's far tamer to it's previous counterpart.
The Bergeron Era (mostly), consisted compilations of videos that featured an individual or more being victim to Screamer Pranks. The Screamer Itself is horrifying, a pale woman with no eyeballs, screaming, which probably scared many kids or at least given a minor scare, despite it's mostly just seen in computer screens. It's also reminiscent of The Maze by Jeremy Winterrowd, or the Scary Maze Game, which is what those videos were trying to replicate (they were mostly Maze reactions), but instead of using the possessed Regan Mac Neil from The Exorcist, it used that other aforementioned screamer, which makes it even worse.
Replacement Scrappy and Seasonal Rot: The Fuentes/Fugelsang era is often considered the show's nadir, and rarely sees reruns. On the other hand, the Bergeron era is often considered at least as good as, if not better than, the original Saget episodes. Alfonso Rebeiro has recieved a mixed reception.
Bob Saget said in an AMA interview once that this is one of the reasons why he quit hosting the show in the first place. As the Internet was becoming popular, people were finding more websites (even before YouTube) for uploading funny home videos. He felt the show had become pointless and he honestly didn't think the show would last much longer after he left.
Suspiciously Similar Song: When the theme was overhauled to the ska-era remix used in the Fuentes/Fugelsang and Bergeron versions, it sounded a lot like "The Impression That I Get" by The Mighty Mighty Bosstones.
You can also apply this to dogs. A lot of this is likely because the studio audience has the final vote, and it's usually filled with either grandparents or young parents. The parents are more likely to find cute videos funny.
Tearjerker: One $10,000 winner filmed her son bawling his eyes out after he accidentally stole a cup from a restaurant. Hearing him plead with her not to report him to the police is just heart-wrenching.
Tom Bergeron's finale. It was very hard to see a great host go, and there was even a little girl who cried for him and kissed the camera.