FFIX - I'm not a big fan of random battles at the best of times, but the battle load times, goddamn. Incredible game, though, I think I was 3/4s of the way through when I had to stop. I loved everything else about it. I will finish it one day, I will, I will!
The worst experience I've had with loading times was with Bayonetta on PS3 (pre-patch) - there is a segment on one of the final bosses where you had to aim Bayonetta's lipstick. (It makes sense it context.) I was shit at it. It took me fifteen tries. (Shaddup.) The loading screens were soul destroying, I think it's the angriest I've ever been at a video game.
I'm surviving the load times with the Witcher 3 on PS4, but damn Dandelion's prolonged re-cap after you load up a game. Shut up, shut up, shut up. Often the plot points are really old if you've moved onto a new area. Any affection I had for Dandelion has been burnt in the Eternal Fire.
(I'd apparently repressed the loading screens re: Normandy's elevator until this thread. I let the fish fucking die, it was too many loading screens.)