82/240 riddles here. :/ I guess I'm nowhere near as thorough as yourself.
And I'm the same now really, I only complete the games I truly enjoy, NFS Hot Pursuit and Dirt 2 I absolutely loved to pieces.
I have completed some other games on my last INFS Undercover (terrible), SEGA Megadrive Collection (Very easy), Terminator Salvation (Shit and easy), Call of Duty World at War (Very fucking annoying platinum.), Resident Evil 5 (Which I do intend to redo since I've done it so many times now I know the game like the back of my hand...)
I actually enjoy the trophy collection a lot, but some games just have all too grueling objectives.. FFXIII in particular - it's pretty ridiculous how much of a pain it is to earn gil in that game, and without gil you can't hope to defeat a lot of the optional bosses\enemies.
Most of the ones I missed were the ones where you had to line up the question marks and such.
For games I really love, having trophies just gives me incentive to play through it again. No matter how much I loved Dragon Age, I may not have gone back with a second character to make different choices and such if there wasn't a list of things to complete encouraging me to do it. At least not right after I finished my first playthrough.
And now that we're talking about RE5, that reminds me that I need to PM Tan.
Ugh, like 12 minutes left in class.
Then I get to sit around for an hour and wait for the next class.