Steam Deck

If you like couch co-op dungeon crawlers, the Champions of Norrath is a lot of fun. Don't forget gems like Dark Cloud 1 and 2, Soul Reaver 2 and Legacy of Kain: Defiance,

I found Ratchet and Clank 3 in the thrift store today, they gave it to me free because I bought a large stack of large plant pots too

I played Shadow of the Colosses on my Potato PC with PCSX2. Took a bit of fiddling with the settings but it ran great afterwards. It's one of my all time favourites. It's an open world boss battler where you defeat giant climbable monsters. They are only vulnerable in specific spots though so in order defeat them you need to figure out how to reach those. The atmosphere is incredible though and the best part of it. If you want try it I highly recommend being hesitant to look up hints for this one since figuring out bosses is the most fun part.

Black.

Mortal Kombat. The one that actually plays like a linear world story, not limited to arena.

@PerfectDark Oh man, I have so many... The PS2 was probably my favorite actual console before the Switch and even then I have so much nostalgia... I think I have a few recommends you may not hear as much elsewhere and a bunch you probably will. Should I dig out my HD and remind myself of things?

Here are what immediately come to mind:

Ar Tonelico 1 & 2 - beautiful RPGs, deep stories, music that blows the mind. Undub of course.
Persona 3 FES & Persona 4 (undubs preferable)
The Burnout games are good to work out some things, lol.
Katamari games of course.
Pop'n Music 11-14
Disgaea 1 & 2 (undubs)
Shin Megami Tensei III (Nocturne)
Melty Blood: Act Cadenza
Tenchu Fatal Shadows (best one in the series IMO)
Tales of the Abyss

Oh geez, I need to dig out the HD. I need to reinstall anyway

One of my favorite games of all time is Dark Cloud. It starts feeling completely alone, and you bring the world to life. The atmosphere and soundtrack are top tier.

Just a side note on Final Fantasy games: you can literally start anywhere. They are all (except like X-2 which is explicitly a sequel to X, and the first time they did that) completely independent of one another.

And since you're talking PS2, I think most people would tell you to start with FFX. It's a fantastic game and a great representative of the PS2 era. The graphics hold up surprisingly well.

Dark Cloud

The .Hack series and SSX Tricky

Neopets: the Darkest Faerie

My favorite was spider-man 2. The story is meh but the combat and swinging physics make exploring the open city SO MUCH FUN. I don't even think the new spidey games manage to replicate the sense of control and speed this game did. Check it out. If you don't want to deal with the story and unlocking all of the moves and upgrades, enter the name "HCRAYERT" without quotes as your new game name. It will give you lots of money, put you part way through the story, and give some upgrades. It's a good way to just jump in and start swinging fast without tutorials or story.

The holy trinity of PS2 platformers is, in my order of preference: Jak and Daxter, Sly Cooper, and Ratchet and Clank.

For Jak and Daxter and Sly Cooper in the first game in the series is pretty different from the rest so if you bounce consider giving the sequel a go.

Gitaroo Man is a pretty deep cut thats hard to find, but I lost plenty of hours in that game. If you find a copy let me know...my disc is torn to shreds.

Ace Combat games are so much fun.

Sweet jebus. You're jumping into one of the biggest (if not the biggest) game console libraries ever. There's a lot to pick from, and... there's a lot of trash too.

It may not be to everyone's taste, but I really enjoy the Burnout series. Each title brings something new to the table, and the music and energy just don't let up. The only problem here is the brutal load times between every level, which on emulation, probably aren't going to be an issue for you. The licensed soundtrack is also something of a time-capsule now, so it may be worthwhile on that point alone.

There are a few Castlevania titles for the PS2 as well. These are a fun departure from the side-scrolling formula, and seem to have learned a few tricks from Devil May Cry. They deliver on mood and challenge, but I wouldn't rank them as high as the GBA or PS1 titles. Still, they're fun to play.

If you wind up short on recommendations, I'll add that PS1 titles should get an honorable mention here. The PS2 is fully backwards compatible with the PS1, so those cream-of-the-crop titles kinda/sorta count. For a lot of us, that was a big part of the experience of owning one of these machines as your library just kept growing into the new console gen. But you've probably already heard of Metal Gear Solid, Symphony of the Night, FFVII, WipeoutXL, Tony Hawk, and so on.

SSX Tricky!!! One of my all time favorite games, i still replay it about once a year.

Some arcade-y faves of mine:

Gradius V: a classic horizontal scrolling shooter, it gets hard quickly! (This is the game series the Konami code originates from)

Neo Contra: a twin-stick shooter inspired by B-movies, also kinda hard, and incidentally also a series that made the Konami code famous.

The Red Star: a bit obscure I think. It's a twin-stick with both shooting and melee. I like the girl's fast melee moves a lot, you need to use combos to juggle your enemies. I think this one got a bad reception because it arrived quite late in the life of the PS2 and was a bit underwhelming graphically.

Dark Cloud or Dark Chronicle, I can't remember which is the PS1 and which is the PS2.

Jak & Daxter trilogy, must have

SingStar.

I enjoyed okami very much! Also need for speed most wanted

Most of my favorite games are already on all the "Top PS2 Games" lists, but my absolute favorite video game of all time is Steambot Chronicles, which got pretty much no attention at all. It's really fun, with nice cell-shaded graphics and a bunch of stuff to do from piloting a big customizable robot to shooting pool to excavating fossils to decorating an apartment to playing a bunch of musical instruments with unique rhythm minigame mechanics! There are a bunch of dialogue options, too, affecting things from minor shifts in how your friends talk about you to a complete alignment shift to the enemy's side, which obviously leads to a few different endings. Regardless of what ending you get you can still do the postgame content, though, so you don't have to worry about getting any kind of "bad" ending. I've played it more times than I can count, and just keep coming back every year or two.

I personally like Star Wars Battlefront 1 and 2. I can't tell you how much I got out of them on an actual PS2 growing up and now on emulator.

Hot Wheels: Beat That! Looked it up, and maybe it's nostalgia making me blind to how bad it actually is, but I don't remember it being a 50/100 metacritic score bad, even the last time I played less than a year ago.

Crash Twinsanity. I loved this Crash Bandicoot game and think it holds up well enough in the gameplay department. It's a long game, so I have less quarrels suggesting it.

Dokopon Kingdom. This is a long and chaotic game. There are probably settings and stuff to get around it, but you might end up like me and have some real seizure level texture glitches that require you to fully restart the game in order to fix. And who knows, maybe in the year or so since I last played, maybe they have fixed whatever issue the game has being emulated.

Shadow of the colossus is a must

Starwars: Racer Revenge was by far my favorite racing game. Not to be confused with the much more popular N64 game "Episode 1 Racer" - the PS2 version was kind of an unofficial sequel that made a lot of improvements. Most notably the physics: the PS2 version actually feels like a pod being pulled by two separate engines, vs the N64 kinda felt like you were driving a car that just looked like a podracer. The physics especially shine if you play in 1st person and set the controls so the L joystick controls the left engine and R joystick controls the right - i.e. to turn left, you don't just push the sticks to the left, you pull the left stick back and push the right stick forward so the right engine accelerates faster and the difference makes you turn. It's super satisfying, if a bit more difficult.

Full disclosure: relying on my memory from shortly after its release in 2002, so I honestly have no idea if it's actually as good as I remember, or if I'm just wearing the nostalgia goggles. Grain of salt.

What are the minimum requirements for running the emulator? I guess it might be game based, but is there a general idea of which processor or graphics card might run some of the less heavier games? (I have an i5 10th gen, GeForce GTX 1060, 16GB RAM)

Jak 3 is still my all time favorite ps2 game.

Silent Hill 2. The game can feel quite dated, but it is an iconic horror game nonetheless

Bombastic

I really recommend Genji and THUG2