The PSP is over 20 years old, I think not a single line of code of it's os and not a single transistor on it's boards hasn't been turned over by the community. It's as cracked open as it can be and especially nowadays fairly hard to brick. They're also very cheap, but the batteries are mostly trash by now.
It has some minding blowingly amazing games that make you question the current hardware requirements of modern realeses.
Highly recommend checking out:
- Monster Hunter Freedom Unite
- Metal Gear Solid Peace Walker
- GTA: Vice City Stories
- Patapon 1, 2
- Ace Combat X: Skies of Deception
Especially the Monster Hunter series had a blooming modding community on the PSP. There are some native ports of PS1 games on the PSP but some also made some homebrew ports.