I have a nostalgic attachment to the Nintendo GameCube. It was the first console I bought with my own money and I spent possibly THOUSANDS of hours on that thing.
In my opinion it's the perfect console form factor. Portable yet dockable when needed, detachable Joycons that can turn into 2 controllers for multiplayer games and a bright and vibrant OLED screen.
it's unfortunate that it's severely locked down by Nintendo, held back by its weak processor and Nintendo dropped the ball with Joycon drift.
By play time on console, xbox360. Also due to it being my console of choice for controller scheme and playing Borderlands, Hitman: Blood Money/Absolution, and a few other things.
Close second right now is probably gonna have to be PS2 since I got one sitting on my desk, I have a.physical copy of the final Ratchet & Clank PS2 title I need to have played every PS2 title in the series (Deadlocked), and it allows me to play Devil Dice since I don't have a PSx.
Easily hackable? Might have to look into that in the future, so long as we aren't talking hardware modifications.
Edit: looks like something I'd try in the future if I ever end up with a spare PS2 because I don't trust myself not to brick my current PS2 somehow, despite the instructions I found being real easy to follow.
I don't think there's much risk of bricking the system, honestly. If you wanted, you could even get a FreeMcBoot card off eBay, and avoid having to do the setup on your own system at all. That's the beauty of the mod - if you know someone who's done it, they can very easily make another modded memory card for you!
My big problem with stuff like that is I know I could probably do it, but I'm worried I'd find the one way that bricks the system. Might look into seeing how much a pre-modified card, though, since I never thought about the whole thing of them being sold online.
I grew up with a Wii and an Atari 2600, and my favorite console is, no surprise, probably the 2600. Both because I put wayyy too much time into it, and because it's incredibly neat from a hardware perspective (seriously, that anyone actually managed to make functioning games on it is a miracle).
SNES. The console had enough power for great games while still having obvious limitations the developers acknowledged. The great SNES games still look and play good today.
The PSX/N64 generation, despite having some great games, has aged horribly because they started chasing that photorealism dragon.
Probably the PS2, for access to the entire PSX and PS2 library. But I'm afraid that it would feel dated if I actually went back it - I haven't played one in years, and it was my childhood console gen, so it's possible it's the nostalgia speaking.