I think my coveted A+ games would have to be Grand Theft Auto 3 for immersing me in a world of witty/black/satirical humor that mixed a mafioso storyline with intrigue, espionage, and general mayhem. If it were a movie, it'd be better than Heat.
Another would have to be, despite my fingers wishing I could not type this... Ocarina of Time. I played that game for a whole summer to beat it. The puzzles truly challenged me, and there was once or twice where I needed to confide in a friend in order to pass a certain section. I slept all day and wa sawake all night playing that stupid fucking game. It was also incredibly gratifying to see the ending cinematic, with Link and Zelda back to their younger selves and in the garden where all of the trouble began. There was something satisfying about that.
Ogre Battle 64 in my opinion, is the quintessential roleplaying game. It had a fantastic, branching storyline, multiple endings, a smart-if-sometimes-difficult combat system, and most of all, immersed you in the world and made you believe that you were the avatar provided for a few hours a day. It was one of the few games where the characters around me became important, and I cherished them like I would my real friends. I mourned the losses, and punished the offenders. A stunning game that really, despite it's cartoonish graphics, should never be forgotten.
Another will have to be Metal Gear Solid 2/3. Epic, cinematic, and well crafted storylines with such a deeper meaning than what you'd expect to see in our medium. They truly blew me away in ways I thought never possible before.
And I think, last but certainly not least... BioShock, but just barely. This game had a few graphical hitches (twitching of dead bodies that were obviously the result of the rag doll physics), and, most of all, it was over too soon. Sure it was a 15-20 hour game, but I just wanted to stay in Rapture... and not to mention the ending cinematics. While definitely satisfying and leaving you with a sense of fulfillment, you just wish it could've lasted a little longer.
Those are my A+ games.