Which is the best MOD Chip for PS1 (US) ?

[Alejew]

I have mod in original PSX unit that works fine. Now I want to put one in my new PS1 unit. Which is the best MOD Chip for PS1 (US) ?

I have numerous sites and they all have (different) MOD Chips for PS1. What is the one that is generally considered to be the best ?

Thanks.