The only one I remember for sure is FF7. My brother and I spent ~2-3 years doing this somewhat casually after our first play through as kids.
All Master Materia, max of every item possible without glitches, all limit breaks, all optional bosses and objectives, all characters max level, every Gold Saucer reward, etc. I still have the memory card with the save file, but I haven't owned a PS1/X for 7-8 years. It was several hundreds of hours.
Pretty sure I 100%-ed AC2 back in the day as well, but I'm not positive. I used to try to go for full completion on most games for a long time, though I usually got bored with collectibles and items eventually.
Haven't had time for all that for awhile, though. I still haven't finished The Witcher 3, Fallout 4, DA:I, MGS:V... just to name a few more recent games. Short on time and then when something new comes out I find it hard to go back to previous games.
Actually, as I was typing this up I remembered we did Majora's Mask as well. Still my favorite Zelda.