All of the best Final Fantasy games were on the PS1 in one form or another. I enjoyed VII the most, but it’s in good company with the VI port, VIII, IX, and Tactics.
The original RE2 is my top Resident Evil game though. The remake was alright, but Mr. X became far more irritating than scary to have to navigate around to finish puzzles. RE5 was nestled in the era when the games got sillier, but it had a great Mercenaries mode & Co-Op.