DaColdFlash's comment made me think of the one game that truly blew me away this generation: Portal

Hmm. Let me see. The ones that really wowed me, huh... ? I will only count games that, to me, brought something new to the table. So for example, I love Twilight Princess to death and think it's the third best game of all time, but it didn't really wow me in a way that previous Zeldas had not (except visually), so therefore it will not be on the list.

1. Super Mario All-Stars - What got me into games to begin with. It's hard to deny how great this gem was.

2. Super Mario World - Took everything I loved and perfected it. It was fantastic.

3. The Legend of Zelda: A Link to the Past & Super Metroid - Taught me that games don't have to be Mario to be awesome. Started them up and played through them too many times to even count, and I still do from time to time. Truly spectacular games.

4. Super Mario 64 - Brought me into a whole new world of experiences, and is, to me, the best game ever made. Truly showed me what 3D was all about (even though I'd played several 3D games on PC before I touched Mario 64).

5. Starcraft - Might well be my most-played game of all time, and pretty much the only game that bound me to PC for so long. The epitome of RTS, and still is better than it's successors in my opinion. Hoping Starcraft II will improve on this massive win of a game.

6. Metroid Prime - What really brought me into last generation was the revival of Samus. Put the Metroid-series into an entirely new perspective and just wowed me at every turn.

7. The Legend of Zelda: Wind Waker - Took the Zelda-formula and put it into a massive overworld with a perfect graphical style that's never going to age. Sure, I prefer realism in Zelda, but Wind Waker is never going to get old simply because it can't look much better than it already does. Only different.

8. Resident Evil 4: Wii Edition - Without a doubt one of the best games ever made, made even better on the Wii due to the Wiimote functionality and the added features from the PS2 version. I've only played through it once but I remember it fondly. The atmosphere, the gameplay, the dialogue, the enemies... It was all just fantastic.

9. Tales of Symphonia - Played it way later than it's release because a friend convinced me to, and it was spectacular. I had been a fan of JRPGs for quite some time, but this one showed me just what a JRPG could be, gameplaywise. Not just turn-based clicking, but actually taking part in the action - and along with a friend. Opened my eyes to the Tales-series, something I will never forget.

10. Metal Gear Solid 3: Subsistence - Played this game later than it's release as well, but it showed me the cinematic effect that a game could bring to you. Sure, I'd played games that were heavily cinematic before (MGS, MGS2, FF-games), but MGS3 really gave me something different. See my MGS3-thread for more clarification.

11. Super Smash Bros. Brawl - I've never been as hyped for a game as I was for Super Smash Bros. Brawl. And it delivered on every front. Fantastic local multiplayer and a cast that makes me explode with nostalgia. Well-balanced characters, spectacular graphics and just overall one of the most polished games I've ever had the joy of playing. I will never forget it.

12. New Super Mario Bros. Wii - This game didn't do that much new(though 4-player multiplayer is superb), and it didn't reinvigorate gaming for me... But it did something even greater. I have periods of pretty serious depression, and during my latest one which had been going on for a few days, I invited four friends over. We chatted, and then when we decided to do something we hooked up the Wii and started NSMBWii. I had already completed the game, so I let the four of them enjoy it together. And just watching the screen, and watching them, within 10 minutes my depression was all gone. Sure, it'll probably be back several times during my life, but I won't forget that moment where it just magically disappeared.

So there you have it.

I don't have that many clear milestones I think. I think they would be:

1. Pokemon - I don't remember how it all came to pass, but I didn't have my very own (legit) Pokemon game before I owned Crystal. Awesome series, that I spent a lot of quality time with.

2. Star Wars Episode I Racer - The first home console game that could just keep me hooked. I have clocked a lot of hours in this game, and it was time well spent! This was probably the defining game for the 5th generation of homeconsoles for me, along with Pokemon Stadium.

3. Spiderman 2 - The most awesome Spiderman game to date, and my brothers and I played the hell out of it. For me, this was one of the two defining games of the 6th generation, the other being:

4. SSX Tricky - This game was awesome beyond belief. If I had to choose one game I would love to see make a comeback on the HD consoles, it would be this. A proper SSX Tricky reboot.

This is where things started to change, and I became more aware as a gamer. When I was younger, I could just play a few awesome games over and over again. But not any more.

5. Guild Wars - The only MMO-type game to ever have me hooked. This game defined my PC gaming years more than any other game, and taught me the meaning of skill and brains in gaming.

6. Warcraft III: The Frozen Throne - I tried to play through the SP, but no dice. I'm not an RTS player. But the custom maps were the star of almost every LAN party I have gone to, and they are still awesome today. LAN parties would be empty for me if not for Warcraft 3.

7. Metal Gear Solid 4: Guns of the Patriots - This game became the reason for why I owned a PS3 once I got it. This is an amazing game, and is still probably my all time favorite. I had never played a MGS game before, but this one still came through, in grand style.

8. LittleBigPlanet - I played through this with my friends, and never before had local coop been so fun. So many hours of pure fun have been had with this game, just playing local multiplayer. It still amazes me.

9. Flower - I had considered games a form of art for a long time, but before this game came along, I had no shining example. But Flower is just that. A game that conveys feelings like no game before it, and is art in every sense of the word.

There, those are the games that stick out in my mind.

Awesome list.  RE4 on the Wii is a must play for anybody skeptical about motion controls.  And it's you last comment that makes me smile.  Gaming gets a lot of bad press, but it got me through a lot of depressing times (including thoughts of suicide a while back) by giving me an escape or giving me people to socialize with.  I remember thinking that if some of those kids who wound up shooting up a school because they felt like outcasts had just found somebody to play with, things would have turned out a lot differently.  I'm friends with a lot of people I'd have never had anything in common with because of gaming.  I'm glad to see it did you some good, too.

1. ??? - i can't even remember the name of the game but it was on the commedore 64. there was a ball that fell down many floors of a sky scraper type thing and it was my job to put various objects along they way so the ball wouldn't fall into any traps. this was the game that made me love video games for the first time.

after that everthing is pretty much obvious; mario, zelda, metroid, wii sports, lbp, ect.

to me MGS2 had a bigger impact on me than MGS3, because of the details that were on the Demo, everything was incredibly detailed and i played the demo hours and hours just messing around.

on MGS3 they toke that and made it better, but the impact is lower because the transition from PS1 to PS2 is bigger than PS2 to PS2.

Earthbound - was one of my first jRPG's and made me fall in love with the genre as a whole

MGS3 - I love the ending to that game, as a military brat it really spoke to me

SotC - first time I saw a colossus I was so amazed just at the idea that I would be taking something like that down, and it only got better from there

Persona 3 - The idea of a dating sim/ RPG as a serious title seemed so silly, but I watched some reviews and they really enjoyed it so I decided to give it a try. Couldn't believe how well those two genres worked together.

Portal - I'm not a huge Half-Life fan so I was surprised at just how much I loved this game. GLADOS' humor was perfect.

Although I would love for it to happen, no game has ever blown me yet.

OT : Only got into gaming in the PS2 era

MGS3 - One word - OMFGWTFBBQAWESOMENESS

Oh my fucking God of War II - EPIC stuff !

Resident Evil 4 - Best Action game I've ever played

Shadow of the Colossus - Unique, artistic, emotional

Killzone 2 - I'm not much of a FPs fan, but this is probably the most addicting, beautiful FPS I've played.

inFamous - Only game that ever had me fully entertained from beginning to end with out a single dull moment... TWICE!

MGS3 - Play it and see for yourself.

RE4 - When you can beat a game 11 times and still want more, you know it's gotta be good.

Games that made me go "wow"?

First game i ever played... Sonic the Hedgehog

Others to add to the list include...
Pokemon Red - Don't really need to explain this. I was 9/10... And it was possibly the best thing EVER at that time. What kid didn't want a real life Charizard? Seriously?

Final Fantasy 7 - My first real RPG experience. Looked amazing, and i wanted spikey hair. Oh, and i have been calling for teh remake for years upon years.

Suikoden 2 - A game i have beaten countless times. If i could offer anyone a "perfect" game, this would have to be it.

Metal Gear Solid - It was Metal Gear Solid, my first time playing it i sucked, the second time i actually beat it and it hit me that i wanted more.

Metal Gear Solid 2 - Was the best looking game i had ever seen at the time, the detail was amazing and it wasn't too long after i had beaten MGS when my brother got the demo. I was hooked from the start.

Metal Gear Solid 3 (;-;) - The first game to actually bring tears to my eyes. Excellent game.

Metal Gear Solid 4 - Matched my expectations, my most wanted game probably... Ever. The ending sequences just had my jaw on the ground.

Valkyria Chronicles (;-;) - Again, surpassed all expectations and brought tears to my eyes at one point. VERY surprising, and gets my vote as best game this gen.

Baldur's Gate 2 - After playing and beating Baldur's Gate, the sound of BG2 coming made me drool. The game was huge... And to this date remains the best WRPG ever released IMO. Way more than 100 Hours of gameplay. Huge list of characters, excellent story and music... Not a fault with this game in my eyes.