Note: I was planning of making this topic for more games, but then again it's easier to find stuff in these games then in others. I've also been writing some stuff for SoM and SD3 and I think this would be a nice little addition to that. Ok so here we go:
In most games, humour from characters usally is from either their attitudes or defaults (meaning the mistakes and errors they make during game play). Since SoM and SD3 are the two simplist games to find these in, I'll go with that for now. I'll make a seprate SoM and SD3 topic like this as it would take way too much space together and may not even fit, belive it or not. This way, it will also help to keep everything clean and on topic.
SoM: The characters in SoM all have attitude based humour as none of them make any laughable mistakes or don't know some basic stuff which is funny. Their reactions to each other is what makes them have one of the best attitude based humour and friendship to each other.
Randi (attitude based humour): This character seems pretty intelligent and makes only a few minor mistakes that don't result in any big laughs (like falling down the waterfall in the beginning). However, his attitude is pretty humerous like how he reacts to Popoie's remarks like "Serve me or I'll send you to my servent Randi!" (said to Gnome) Randi's reaction was "Hey, who are you calling a servent?!" (and makes a funny annoyed face). His bickering with Purim is also pretty funny as they both seem to have love-hate relationship thing that's going on which none of them seem to want to admit to one another.
Purim (attitude based humour): Purim's status protecting attitude is the thing that makes her attitude most humerous like Randi, although a bit more with her. The best example is first seen when the Gnome thinks that Purim was Popoie's wife. Her reations result in the same funny and annoyed face that Randi had and a comment: "Me, married to that?!". Her constant bickering with Randi also results in pretty humerous scences.
Popoie: This is un-doubtably the most humerous character in the game as he gets both Randi and Purim going with his timeless remarks and comments. Some examples are listed above with the other characters. Even when he doesn't get Randi and Purim annoyed he can still come up with some great stuff like "Rats eat all the food!".
I'm pretty much done here. I'll get started on the SD3 one, then I'll think about making the mythology and lore refrences in SoM and SD3. I may also do some stuff for SwoM too when I get the chance and if I find some good to write about it. Even though I beat that game quite a lot too, I don't have a lot to say about it since it's a remake of FFA. I'm not sure if that was worth editing this post for, but I just thought I'd mention it.