A note: Try to track down the Game of the Year Editions of various games when you can. With the PS3 being as old as it is, I'm not sure how many patches and DLCs are actually available anymore. And a lot of GOTY editions have the DLC included on disc.
And I'm not sure if the digital store for the PS3 is still up or not. There's a few good digital only games on the PS3, but I'm not sure if you can still get them or not. It might be impossible to even put money into a PS3 era Playstation Store account. So, I won't mention anything that's digital-only.
Also, you might want to check if the model of PS3 you have is backwards compatible with the PS2 or not. Not all PS3s are backwards compatible.
Also, I tried to make sure there aren't any M-rated games outside those in their own section. But, maybe just double check, because some might end up slipping through.
Point and Click/Story games-There aren't a lot of these for the PS3. And almost all the good ones were the Telltale "episodic" series, which might be gone along with the PS3 digital Store. You could try tracking down stuff like the Telltale Walking Dead, Wolf Among Us, or Batman physical versions. But, all of those are M rated, anyway, so they might be vetoed. And even the physical versions might not be complete on disc, anyway.
There's visual novels like Steins;Gate, but that's M rated, too.
The Sam and Max Telltale games would probably be pretty fun...but they might just be gone along with the PS3 digital store, I'm not sure.
Puzzle Games:
Portal 2-Kind of a mind-bending puzzle-shooter. If you can find the Orange Box, that might be worth picking up for the first Portal, alone.
Little Big Planet 2-Probably the best out of the series. It's more of a platformer with puzzle elements. Kind of a Mario Maker sort of thing, but it has a single player mode, too.
Katamari Forever-The Katamari games are simple, but fun.
Ico and Shadow of the Colossus Collection-Very moody and atmospheric. They're a different kind of action and puzzle games.
Racing Games: I'll admit, I don't play a lot of racing games. But, here's some highly rated ones.
Burnout Paradise-Everyone seems to love this one.
Need for Speed Hot Pursuit-Another highly ranked one.
Gran Turismo 5-This actually seems to have better reviews than GT 6.
Split/Second-Kind of focuses more on the crashes.
Blur-More of a combat focus.
Dirt 3-More of a gritty one.
Motor Storm Pacific Rift-Another more off-road focuesed one.
Sonic & All Star Racing Transformed-Just for something a little different. I don't know if he's "too old" for kart racers or not, but this is a good one.
The Collections: The PS3 had a BUNCH of collections of older games, which are a great value.
Sonic's Ultimate Genesis Collection-Probably the best collection, if you love classic Genesis games. You get ALL the Sonics and a bunch of beloved classics. Best bang for your buck on the system.
Ratchet and Clank Collection-You get 3 great games.
The Sly Collection-You get 3 great games.
Jak and Daxter Collection-You get 3 more great games.
Prince of Persia Classic Trilogy-They do get more violent as they go along, but this includes the Sands of Time Trilogy.
Kingdom Hearts 1.5 Remix and 2.5 Remix-This gets you most of the way with the Kingdom Hearts series.
Final Fantasy X and X-2 Remaster-They're solid JRPGs.
Disgaea Triple Play Collection-It's got 3 highly rated Japanese Strategy games in there. So, you get great bang for your buck. It just depends if you're into something like Fire Emblem or not.
Adventure games: I might be a little loose with my definition, here. But, these are at least "action-adventure" games.
3D Dot Game Heroes-It's basically Zelda crossed with Minecraft. It's a fun time, if you can track it down.
Transformers War for Cybertron and/or Fall of Cybertron-Both are solid action games.
Transformers Devastation-A incredibly pretty and fun Transformers game.
Batman Arkham Asylum GOTY and Arkham City GOTY-Both great games, if you've never played either of them yet.
Ratchet and Clank Future A Crack in Time-Probably the best the the "new" R&C games for the PS3.
Ghostbusters the Video Game-So good that it's basically considered canon.
Spider-Man Shattered Dimensions-The ORIGINAL Spider-Verse!
Star Wars the Force Unleashed-Probably the best Star Wars game on the system.
Dragon's Crown-It's more of a beat-em-up. Some of the character models might be a little iffy, but it is a good game.
Enslaved Journey to the West-A kind of forgotten gem based on Journey to the West.
Tales of Symphonia Chronicles-You get one all time classic action RPG...and it's middling sequel.
Dynasty Warriors Gundam 3-You get to mow through crowds of giant robots. If you're not a Gundam fan, it might not mean as much to you. But, you'd still have a fun time, even if you don't know the series.
Odin Sphere Leifthrasir-Another fun beat-em-up like JRPG.
Uncharted 1-3-They get better as they go along. They are classics!
El Shaddai Ascension of the Metatron-It might be worth trying out just for something different.
Journey Collectors Edition-These are more "walking simulators", but it was highly rated and influential, at the time.
Lego Star Wars The Complete Saga-Again, I don't know if your son is "too old" for this. But, this is probably one of the best Lego games.
Marvel Ultimate Alliance-More of a real time strategy game, but it features a LOT of Marvel superheroes.
Fighting Games:
Ultra Street Fighter IV-The best version of the fighting game that revived the genre.
BlazBlu Chrono Phantasma Extend-A anime fighter.
Guilty Gear Xrd Revelator-Another anime fighter.
Platformers:
Ducktales Remastered-If you have any nostalgia for the old Ducktales cartoon, this is just great.
Sonic Generations-For a long time, this was the best Sonic game in recent history. They are just about to release a remake, though, so if you have a current system, you might want to just wait.
Puppeteer-Kind of a stylish platformer.
Rayman Legends-Another stylish platformer.
RPGS:
Ni No Kuni Wrath of the White Witch-A Ghibli style JRPG. It can be a little grindy, though.
Legend of Heroes Trails of Cold Steel 1-2-They're good JRPGs. They can be dense, though. And they kind of end of a cliffhanger that's continued in the third and fourth games only on the next gen.
Valkyria Chronicles-It's a good strategy game. If you like something like Fire Emblem.
Violent games that might be JUST on the edge of being vetoed by the wife (The M rated stuff). Unfortunately this is probably mostly stuff you're going to have to avoid, maybe. None of these are horror games, but they might still be too violent or crass for your wife to want them around:
Assassin's Creed 2 or 4-These two are probably the best in the series. I'm not sure if they'd be too violent or not, though. But, they're not horror games, so I'll list them.
Borderlands 2 GOTY-A great tongue-in-cheek shooter.
Brutal Legend-Jack Black fights a army of demons with the power of rock! It is M rated, though.
Zone of the Enders HD Collection-Here's a space shoot em up! It's about robots, but it should scratch that itch. Unfortuanately, it's also M rated.
Darksiders 2-It's Legend of Zelda like. But, again, M rated.
Deadpool-Again, it's a fun shooter. But, again, it's M rated.
Metal Gear Solid Legacy Collection-You get the first 4 games. But, again, M rated.
Metal Gear Rising Revengence-So stylish! So action packed! But SO VIOLENT!
Devil May Cry HD Collection-It's more "action" than "horror", but it does feature demons. You get 3 games, though.
God of War Saga-You get the entire original trilogy. But, it might be too violent.
Elder Scrolls IV Oblivion GOTY or V Skyrim Legendary Edition-They're good RPGS. Again, they're M rated.\
Vanquish-A stylish shooter. Also M rated.
Mass Effect Trilogy-You know the drill by now.
Red Dead Redemption GOTY-You know the drill by now.
South Park the Stick of Truth-You know the drill by now.
