PCSX2

The PS2 library at a resolution the PS2 never managed.

What it does

PCSX2 emulates the PlayStation 2 — a famously awkward machine, with its Emotion Engine, vector units and a graphics synthesiser nothing else resembles. Compatibility is now well above 95% of the retail library, with internal resolution scaling, texture filtering, widescreen and 60Hz patches, save states and per-game configuration.

The Qt interface handles game libraries, and the automatic settings database applies the known-good workarounds per title so most games need nothing configured.

Notes

Needs a PS2 BIOS image dumped from a console you own. The project does not distribute one, and will not run without it.
Apple Silicon builds are native and recent; anything found from the 1.6 era is Intel-only and much slower under Rosetta.
Emulation is lawful. The BIOS and the discs are yours to dump.

Alternative to

Alternative	Type	Trade-off
DuckStation	Open source	The PlayStation 1 instead, from the same corner of the scene
RetroArch	Open source	PCSX2 as a core, behind the standalone build
RPCS3	Open source	The PlayStation 3, and still rough on macOS
A PlayStation 2	Paid	Original hardware, 480i, and a disc drive that still works or does not