Well, Disgaea for the PlayStation 2 kind of comes to mind. It is SOMEWHAT violent, and the humor is a touch crude at times, but it's done in a very amusing way. You have to love a game with exploding penguins don't you? It's all cartoon level violence, so no blood and gore, and when you kill an opponent they just kind of poof out of existence. The overall story might be a good one too. It's about the path of a selfish, arrogant, untrustworthy daemon learning to love. Considering you style yourself an "old fart" you are probably the sort of person who can look past some crudeness when it's done for comedic effect. Along the way is a lot of really great humor that, so long as you are able to look past a slightly crude nature, you'll probably enjoy. That way there's a little something for the both of you.
It's what you'd call a strategic or tactical RPG. You have a series of characters, the opposing side has a series of characters, and then you move along a grid. Some parts of it may be a little involved, but you can kind of help your kid out with that. You can also get some considerable mileage out of this game. A good player would probably require 60-80 hours to complete the main story, and then there's 2-3 alternate endings, and the daemon senate and item world where you could literally spend hundreds of hours.
You can probably find some videos of the gameplay on YouTube and the like. IMO, you should search for the Prism Ranger bit, where they take a stab at the old Power Rangers TV show.