I found Osomatsu-san to be pretty similar to family guy in a few ways, I'd call Osomatsu-san the Japanese Family guy.
Both shows have a similar sense of comedy in a way. Sure, the jokes, gags, and punchlines are completely different, but the one thing that they have in common is that jokes drag on for such a long time. Just like Family Guy, Osomatsu-san has a lot of jokes and scenarios that could have been funny if executed in a timely manner, but instead, some stupid scenario that should have been one minute long goes all the way anywhere from 2 minutes to the entire episode. Plus, when it comes to the "creative" scenarios, just like Family Guy, it's some lame joke/setting that happens to be the basis for the setting that everyone's in for the next 10 minutes. However, just like Family Guy, Osomatsu-san's jokes can still be funny.
Osomatsu-san clearly has a lot of creativity when it comes to the generation of scenarios for each episode. As a result, it's a very mixed bag. I'd I skipped 25% of the scenarios in total, 50% were "meh, alright," and 25% were "pretty good." F-6, Samurai/Edo theme, detective, Osomatsu girls, the "scary, realistic" scenario, and a bunch of other skits were just so bad I had to skip them. The theme here is that everything related to these scenarios are just absolutely random and don't make any sense at all. There's an attempt to create comedy with the sheer randomness and nonsensical action that goes on, but it just ends up being a random scenario that drags on for too long. This is especially so for the recurring themes and settings, like F-6 and Osomatsu girls. Seriously, they weren't remotely funny in their pilots, so why bring them back?
As for the others 75% of the scenarios, they were reasonable enough that I didn't skip them. Again, some of the absolutely random scenarios also land in here. They were entertaining enough, I guess. But for the most part, the scenarios that were good enough to watch were the ones where the character personalities of the sextuplets are able to shine. When you just have random crap going on, the scenario takes basis for the entire time, while the sextuplets are just dragged on for the ride. It's like their personalities didn't even matter, and it could have been anyone subbing in for their roles in the scenario.
I like the idea of a comedy featuring a family of sextuplets because there's so much freedom and opportunity for comedic scenarios. 6 Varying personalities make for the ability to be flexible with dialogue and settings. However, for the most part, the personalities of the 6 brothers are barely explored at all. My personal ranking is as goes: Choromatsu, Todomatsu, Osomatsu, Jyushimatsu, Ichimatsu, and Karamatsu. The first 3, you could argue first 4 on my list have some distinct personality traits that aren't just limited to the same dialogue and same role in different scenarios, while the last two just are completely static characters that have the least change in any of their roles in the scenarios. I really would have liked for there to be scenarios featuring only a few of the brothers at a time to make their personality shine, or even just one of the brothers interacting with the rest of the cast. Sadly to say, while these scenarios happen, they're few and far between. For the most part, they're together. Well, that's okay too, you can showcase personality, and you could say the volatility of the sextuplets are endless! Yeah, for the most part, the character dynamics are not the greatest. Their personalities are extremely limited and left unexplored. I get that this is a comedy, but even for a comedy, this is unacceptable. There's a base line of good characters that need to happen for a comedy. After all, even if the scenarios are funny, if the characters don't have good dynamics with each other, it's for nothing.
And it's not to say that these personalities are unsalvageable. My favorite scenes were the Kotatsu one and the Majhong one. Both are pretty generic scenes when it comes to the scenario, but that's where the personalities of the characters really shine. The sextuplets' personalities were put on showcase, and that's what made it great. And yes, it's not like random scenarios aren't funny. Gintama's a great example. Some of the scenarios are crazy sci-fi crap and a lot of it is nonsensical, but Gintama's scenarios still manage to keep characters at center stage, reacting to the scenario at hand, rather than the scenario dragging their hand along for the ride. It's just so sad to see Osomatsu-san have so much garbage laying around because they want to play it safe and just pile on random scenarios in hopes that this randomness will be funny despite it having absolutely dull dialogue and character interaction.
I mentioned this at the very beginning, but Osomatsu-san has jokes and gags that should have lasted 1 minute last 10 minutes at a time. Any sort of comedic value is lost by how long they drag them out. Just move on to the next scene, thanks. I really would have liked there to be scenarios where they're long and involve some crazy setting, but it's still just the sextuplets' base personalities without any sort of random theme that they're shooting for.
I say some harsh things, but truth be told, this is a show where I laughed a few times and had a good time at others. This is much better than other comedy show. Sure, a lot of scenarios blow or are mediocre, but there are scenes where Osomatsu succeeds at being funny.
I tried watching through Osomatsu-san's season 2, but it just amplifies the garbageness and doesn't try to do anything new. The only remotely funny episode was where Choromatsu and Ichimatsu were talking together, and the other ones just have the same exact problems but magnified. Scenarios take over the show, and the sextuplets are just a backdrop and stick to their pet lines and roles over and over again.
Osomatsu-san is a series that had potential, but the "creativity" and lack of structure, comedic timing, and good character interactions makes it a mixed bag.