GoKawiilTo make this a little easier to break down, let's pit the best GameCube emulator against the PS2's finest. When it comes to providing the most accurate retro experiences, GameCube's Dolphin emulator is generally held in slightly higher regard than PCSX2. To be clear, both emulators have evolved to the point where they run a large amount of both consoles' libraries well on modern PCs and the best gaming laptops. According to OC3D as of 2023, Dolphin can emulate 97 percent of GameCube games, while PCSX2 can play 99 percent of PS2 titles.
Both Dolphin and PCSX2 are free, open-source emulators that allow you to play GameCube and PS2 games respectively on Windows, macOS and Linux devices (Dolphin also runs on Android). The main differences between the two when running old games on modern hardware is that it's slightly easier to emulate titles on Dolphin than PCSX2, as Dolphin doesn't need quite as powerful a GPU as the PS2 emulator.
Thankfully, neither program requires a top-tier video card like the Nvidia GeForce RTX 5090. If you want to experience your favorite early 2000s titles on Dolphin at 4K/60 FPS, a graphics card like the RTX 2060 or AMD's Radeon RX 5600 XT will do you just fine. With PCSX2's somewhat more demanding hardware requirements, you'll give yourself more headroom with an something like an RTX 3060. Emulation requires more powerful hardware than the original systems due to the involved overhead, not to mention their graphical upscaling.
While both emulators are pretty easy to set up, PS2 emulation is trickier owing to the awkward composition of the PlayStation 2's CPU. Sony's bespoke Emotion Engine was co-developed with Toshiba and built around parallel processing. Though this gave developers at the time a lot of flexibility, it also made the PS2 infamously tricky to program for. The fiddly nature of the Sony machine's CPU has made PS2 emulation a little more difficult than emulating games through Dolphin, as the GameCube uses a more straightforward IBM "Gekko" processor.
So while it's close in overall emulation quality, the GameCube's Dolphin program just edges out PCSX2 due to its less demanding nature.