PS1
Most memorable game - Tekken 3. Tekken 1 was the reason we got a PS1; Tekken 3 represented the peak of the series for me, and is both my favorite PS1 game and one of my favorite games on ANY console.
Most time spent on a game - Honestly, I can't remember. We played a lot of fighters for a while, and I was really young back then. I couldn't tell you which one we spent the most time with.
PS2
Most memorable game/most time spent: Final Fantasy X.
PSP
Most memorable game - Both God of War games (tied). What Ready at Dawn was able to pull out of the PSP is still a marvel to this day.
Most time spent - The Dissidia games. I'm a sucker for fighters with RPG elements.
PS3
Most memorable game - Bioshock 1 and Arkham Asylum (tied). Even though I still haven't finished either of them. :p
Most time spent - Dynasty Warriors Gundam 2. I don't know why I love these Koei hack-and-slash games so much; I just do.
PS Vita
Most memorable game: Soul Sacrifice. Best game I've played on the system to date, despite it's flaws.
Most time spent: Dynasty Warriors Next. See above. :p
Have some time to kill? Read my shitty games blog. http://www.pixlbit.com/blogs/586/gigantor21
:D