I may not interpret the 10/10 thing as completely flawless so much as greatly enjoyable for multiple playthroughs without any super debilitating flaws that take away from the experience. I don't think being utterly flawless is so important anyway; I wouldn't define perfection as a lack of flaws in the context of video games.
I know there's a pretty massive bias toward older games, so I'm going to lead off with a newer one: Mass Effect 2. Easily my favorite current gen game, it's impressed me that the Mass Effect series has managed to be a lot of things I hate on the surface -- I don't like games where I have to use firearms, I don't like space as an environment, I typically don't like a lot of non-human characters -- but I think it speaks to an excellent game when I love it in spite of these things. Gameplay on higher difficulties is rewarding and thrilling, forcing the player to make sound tactical decisions and develop strategies. The plot is strong in spite of bridging ME1 and 3, and the game does a nice job of making you care about your squadmates and Shepard... making the endgame mission where everyone can permanently die and not be available in Mass Effect 3 frantic and emotional. Add in some great music and voice acting, and it's a great example of what this generation of consoles can do when the developers put some effort in. My favorite current gen title over games I've spent a ton of time on like BioWare cousin Dragon Age: Origins, WoW, RDR, etc, and it's not even close. Scary to think ME3 could be even better.
A game that has already gotten some more love is Final Fantasy Tactics. The gameplay is spectacularly good if you keep off of some of the more powerful units (Orlandu should never have been given to you, Reis is stupid, calculators are insane, etc.), particularly if you partake in the early Smogon pasttime of Single Class Challenges. I pretty much exclusively SCC now, and every time I replay the game stays fun and challenging. The plot is delightfully dark for a Final Fantasy even if it was probably translated by Fawful, and it has a very fitting soundtrack I dearly missed when playing the letdown that was FFTA.
I actually hated it the first time I played through, but once I got over my Chrono Trigger fanboyism after how badly the original cast was thrown aside I grew to respsect Chrono Cross. Boasting easily the deepest plot for an RPG of its generation (check GameFAQs; there's a ton I didn't realize was there on my first couple of playthroughs), CC gave some interesting plot elements with the parallel worlds and some memorable characters with Kid and Harle, who I still consider among my favorites from video games. The combat was innovative, if not super challenging on repeat playthroughs (I have to stop myself from trapping in the Dead Sea to avoid trivializing the second third of the game). I think the artsy elements of the game deserve special mention -- I'm not sure what I think about the idea of video games as art, but many of the tropical locales and some of the more surreal ones like the Dead Sea and that Dimensional Vortex where you meet Sprigg, and the music that plays at them... it's something special video games don't normally have. Shoutout to Prisoners of Fate, Scars of Time, and Unfathomed Reminiscence, I believe are the track titles. The game's only big flaw behind crushing CT's heroes was having way too many playable characters, and as a result having many identical lines written with different accents... it's pretty avoidable by keeping the plot characters in your lineup(Kid, Glenn, Harle, Norris, etc. all have more unique lines), and not enough to detract much from a great game.
I'm a big fan of the Metal Gear series, but I have to tip my hat to Metal Gear Solid by virtue of it being the only 3d Metal Gear that didn't let you shoot in first person, forcing you to sneak more, as was intended. I'm pretty sure if you're supposed to be undetected that trail of corpses gives you away, and latter entries became more about disabling enemies than avoiding them... Anyway, a game that tries to make you AVOID combat has a special place in my heart in a world with games like GTA, and having to think some about the best way to handle a situation always does it for me. Some of the best storytelling in a video game with some incredibly well developed characters like Snake and Naomi, boasting fully voice acted lines back on the PSX... and doing it better than most PS2 and later titles. The game even managed to tear at your heartstrings a bit with Otacon and Meryl(especially since she wasn't a huge bitch yet), which was a pleasant surprise given how grim a game about sneaking into to a facility taken over by a rebel army to deactivate a nuke is on the surface. Some nice humor with Snake's dry wit and some of the Hideo Kojima trademark stuff. Also had maybe the best boss ever with Psycho Mantis.
Some games that are a lot less perfect than the above I wanted to mention:
Dragon Age: Origins would have been my favorite this gen if not for ME. Some amazing characters -- Morrigan, Alistair, Zevran, Leliana, and Logain can stand against anyone and reasonably good tactical combat until you learn too much. Roleplaying as good as a video game has been. So much better than its sequel.
Final Fantasy X: No sphere grid FFX is my favorite balance of gameplay in an RPG to date and I love the way the speed stat works with the turnbased combat to keep things tactical. Aeons are so fuckin cool. Only FF that sold me on the love story. Loses big points for laughing scene, the scene as you enter Luca, sometimes shoddy voiceacting, Tidus being exaggerated in the first half of the game, and Auron in general. From "Home" on is maybe the most beautiful 10-15 hour span we've gotten out of Square.
Monster Rancher 2: my second favorite video game series to Mass Effect, would suggest this to anyone. Combat has almost as much RNG as pokemon but it took me years to really get great at combining and raising monsters and it's still not easy to get something great(and near impossible to max out). Huge variety in monsters, cerebral gameplay for a monster game, addictive gameplay... if Tecmo had the marketing budget Nintendo did I might be on a monster rancher forum right now.
Dragon Warrior Monsters: another monster game I prefer to playing Pokemon with myself. Gameplay was a little limited and repetitive if I look at it objectively, but was always fun and addictive to me. Lots of complex breeding options to get the best monsters, which made putting effort in more rewarding than silly stuff like IVs in Pokemon. Shared a flaw with MR and Pokemon in that there was very little plot to speak of.
