Off the top of my head…it’ll take way too long to figure out my best one:
Super Mario world
Halo: CE
Super mario kart
Street fighter 2 CE
KOF 98
Ocarina of time
JSR
COD:4
BF:BC2/3
the list could go on…
Morrowind: GOTY Edition
Deus-Ex 1
SF2
Ninja Gaiden Black
Star Wars: KOTOR
Perfect Dark
Shenmue 1/2
RE4
WWF No Mercy
Earthworm Jim
Splinter Cell: Chaos Theory
This is most likely my top 10, starting with Morrowind at #1. There are a few titles I might shuffle higher or lower, all I know is the #1 and #2 spots will remain the same. I would rate Shenmue higher if the damn story were finished. 
Honorable Mentions: Wario Land SML3, Mass Effect 1-3, Orange Box, Full Throttle, Donkey Kong 1, NBA Jam, Breakdown, SFA 1-3, Deus-Ex: HR, Mirror’s Edge, Gears of War 1, Halo 1/2, Super Mario, Mario 64, Zelda: OoT, Goldeneye 007.
Okami
Okami
Portal and Portal 2.
Chrono Trigger.
Resident evil 4 is da bes. Period.
Ocarina of time
Donkey Kong Country
Smash bros 64
Mario 64
Bioshock
Lierox
Lumines II
Whenever i do this i always miss a ton but whatever.
Zelda Link to the past SNES
Metal Gear Solid on original GameBoy was amazingly good.
Super Castlevania IV, Castlevania SOTN, Final Fantasy Tactics, Final Fantasy 6, Marvel Vs Capcom 2, The Battle of Olympus, Super Metroid, Zelda A Link to the Past.
I can’t pick one favorite out of all these, I care about them equally.
Super Metroid.
The game is beautiful. The visuals, ambiance, and music together give it this palpable atmosphere that very few games even to this day can match. More than anything, the atmosphere is what I love.
Deus Ex 1
Super Turbo.
Greatest game of all time.
edit: Gotta have my coffee before I post next time.
To this day I play MGS like a mad man
http://img.tapatalk.com/d/12/09/05/8unanypy.jpg
But my other favorites are
http://img.tapatalk.com/d/12/09/05/a3umuhed.jpg
I’m surprised this hasn’t been mentioned(if it has, I’m sorry)
http://img.tapatalk.com/d/12/09/05/vebarape.jpg
http://img.tapatalk.com/d/12/09/05/ba9yqagu.jpg
http://img.tapatalk.com/d/12/09/05/adaza4um.jpg
http://img.tapatalk.com/d/12/09/05/ga3asame.jpg
Infamous 2
Destroy all huamans 1&2
Monster hunter freedom unite
I have a lot of favorites. I was always a PC gamer, because I was too afraid to ask my parents for a PS2. Any PS2 games on my list were played by borrowing my friend’s PS2.
MGS 1&3
Splinter Cell (everything before Conviction)
Hitman (all of them)
MvC2
Age of Mythology
Starcraft
Portal (still have to play Portal 2)
Half-Life 2 series (gotta get HL1 series off steam ASAP)
Mirror’s Edge (a new gen game that’s actually difficult? who knew?)
Populous: The Beginning (this game defined my childhood)
Pharaoh (another big part of my childhood)
Super Smash Bros Melee
Can’t pick just one.
Valkyrie Profile 2: Silmeria It wasn’t like the first one and I had to get used the running around monsters and the grid. But once I did, it was fun again. I just loved the battle system. Just fucking fun and perfect and awesome. And the voice acting wasn’t VP1 but still great.
Soul Crushes. I fucking loved these.
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Valkyrie Profile 1 - The perfect RPG for me. Just perfect. Sidescrolling elements. You can pick who you want to fight and if you hit them monsters from behind you get that free opener. The voice (over)acting was just so fucking awesome. And the fighting quotes… my god… I say them to this day. For no damn reason.
To my side my Noble Einherjar!
It shall be enraved upon your soul!! Finishing Strike… NEBILUNG VALESTI!!
I used to do a run through the Seralphic Gate once a day because I loved that game so much.
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Batman: Arkham City - They took 1 and made it ridiculously awesome. There is no part of this game that I don’t adore. Taking down 35 guys with various counters, weapons, attacks and planning is absolutely some of the most satisfying shit I’ve ever done.
This has been THE INVINCIBLE SWORDSMAN saying:
There are more that are incredible but these 3 just stick out. The battle system… Fighting is fun = A great game for me.
Yoshi’s Island, Super Mario World, A Link to the Past, Resident Evil 3, Final Fantasy XII, VI, and Tactics. Out of these, Yoshi’s Island is probably the greatest game I have ever played.
EDIT: I came back to say why these games are amazing, and then I realized that I absolutely sucked at explaining why they’re amazing. I just sound like an idiot. All I can say is that every game was incredibly fun, and the FF games had really good characters and story. Except for XII, Vaan, Penelo, and Fran all suck, but the battle system makes up for that. I didn’t even set up gambits besides Cure and Raise; I just manually casted everything. Made the game much harder, and much more rewarding.
To this day I’m mad at not being able to re-find this OR Yoshi’s story. I need to get my Wii, I’m sure all the games from my childhood are just sitting waiting for me to grab at them…
1- OoT : The first game that made me play it. It had all I needed when I was a kid good combat, fun expansive worlds, gripping story, awesome dungeons (including the water one, gave me no trouble as a youngin) great characters (Zoras and Gorons were the fuckin shit. Even though Gorons scared me a little bit). I haven’t replayed it in YEARS (a decade? holy shit I hope not…). Gonna find it and play it to see if it holds up to how I remember it.
2 - DKC2 Diddy’s Kongquest : Yeah, DKC2, game took up a whole bunch of my childhood, and DKC1-3 ate up my summer 2 years ago. They’re still good to me.
3 - Braid : Play this game if you have any sort of interest in platform games. Mechanics are fuckin amazing, music is a gift to your ear-balls, story is quite good (and open to interpretation) and one of the most memorable endings I’ve ever seen. PLAY THIS GAME.
4 Madden Of Duty 6
I need to get Shadows of the Colossus and Ico. Dammit. Currently playing Silent Hill 1, and the MGS: HD collection staring me in the face (I beat 3 though amazing).
I’m gonna be the weird kid who says Fire Emblem. Not sure if I like the one with no subtitle in the US or Path of Radiance better. Still need to check up on Genealogy of the Holy War, though.