Sorry for the wall but considering I focus a lot of my energy on the Playstation, I figured I might as well just say that as far as emulators go with the Playstation 2, it's not going to be the best bang for your buck. If you want the best of old school consoles for oldschool emulation and with the best variation, with hardware alone if you're insistent on a classic console you should be running an xbox classic model. Which are more powerful than a PS2, and can emulate a PS2 game much better than the PS2 itself.
Some PS2 games I've seen it struggle with when it comes to emulation via Mcboot personally is games like Klonoa 2, where if you hit a moomoo's shield the game can crash. Though that could just be my card being too full, and same goes for Yu-Gi-Oh Duelists of The Roses, another exclusive to the console. Also a small thing you should keep in mind while using a Mcboot is that if you just hit the reset button while you're playing the games file can easily get messed up and the easiest way to fix that is by just deleting the games file on your Mcboot card on your PC and then putting it back into your PS2.
Mcboot from what I also understand will require you to mess with power settings if you're playing a PAL region game, considering if I remember correctly PAL region consoles and games need different voltages than what most if not all US and JPN consoles will put out there.
Anyways, for the PS1 fans out there too, I should mention that the Playstaiton 2 isn't even the best console you could be running for emulating, letalone playing your Playstation 2 or Playstation 1 games. If you need something that gives you a good idea of what I mean, Megatudo 2096 is a great mecha fighting game for the PS1 that was only released in Japan
that doesn't actually have the best backwards compatibility with the PS2 console itself as it will lag on official hardware for example.
Also another general note: you shouldn't load up your Mcboot card crazily, as that will make it more prone to lag issues, loading issues and more. Something that should be noted is that videogames are very tricky, especially with emulation, and though we've gone a very far and long way since the 90s, we need to understand.
So if you want to know the best you can do with your PS2 slim with a FreeMcBoot, you're able to:
> play backup games depending on what else you have installed on there.
> play most, not all but most PS1 and PS2 games from Japan and the United States. (assuming you're using an NTC-USA console slim release)
> have a lot of viability in playing SNES and NES games.
> have some games operate slower or faster depending on your set up and the game you're playing. Plus the memory card you decide to use for your mcboot set up and what SD card is holding your games.
> Should have access to some old MAME games for your console.
But that's a very general and brief list. Hopefully even with this lengthy wall of text, it gives a lot of people what they hope to know.
For the future, if people want to use a Playstation console for emulation in Playstation games, you're more likely to get better results with a PS3 - PS5. But if you really insist on using an old school console for emulation and you want the most options for your money, straight up just use an Xbox Classic. They're durable,
and though Xbox systems have a very serious design flaw, that's still very easily corrected.
Tl;Dr, you should be able to play most games from the PS2 and PS1 library with some difficulties depending on your model and make. PAL region games may require some messing around to get working properly, and you should be able to play most games from prior consoles unless you're playing something like a SEGA CD, SEGA Saturn, or Dreamcast Game or something of that sort. That or like, an Xbox classic game. If you're wanting something that can reliably play all of your PS2 games via emulation, the PS2 though is a great option or good start, you'll get your best results with a different console. I hope this helps.
