1. The Legend of Zelda: Wind Waker - despite having loved Ocarina of Time and Majora's Mask, there's something about Wind Waker that will always make it my favorite game of all time. The graphics were gorgeous, and I, for one, loved the sea travel.
2. Kingdom Hearts - my sister introduced this game to me. Having been a huge Disney fan, I was drawn in by Kingdom Hearts, and I still replay it (and the sequel), once a year.
3. The Sims (series) - I'm not a big PC gamer, but The Sims fits the bill when it comes to the word "addictive". I play The Sims 3 almost every day, and I'm still discovering new things and making new stories.
4. Super Mario Galaxy 2 - as a big platforming fan, I fell in love with Galaxy and its sequel. They are platforming at its best, and I can't think of a better game to play when it comes to Wii.
5. Pokemon Red/Blue/Yellow - my first video game of all time. Self-explanatory.
6. The Legend of Zelda: Ocarina of Time - I had trouble placing this in my list. As much as I love Ocarina, I didn't know whether it belonged at the top or bottom of my list. I settled on #6 because, at the time, it was masterful, and even today, it still holds up thanks to an excellent 3D remake.
7. Professor Layton and the Curious Village - I was reluctant to climb aboard the Prof. Layton train. I wasn't a big puzzler back in 2008, but I'm glad I did. Everything, from the voice acting to the mind-bending puzzles, is perfect, and I recommend the entire series to every DS owner.
8. Goldeneye 007 - I played the original much later than everyone else, and I still found Goldeneye to be FPS gold. It set the standard for the modern FPS, and without it, I doubt we'd have Call of Duty or Halo.
9. Sly Cooper (series) - more platforming gold, and my first game for the PS2. I fell in love with Sly and the gang, and it was a shame to see the series end.
10. Super Smash Bros. Brawl - when I think of multiplayer, the first thing that comes to mind is Super Smash Bros. I've logged countless hours into this game, and more are added very often, since it's the go-to multiplayer game on Wii.
Honorable Mentions:
Pokemon Gold/Silver
Pikmin
Uncharted 2
LoZ: Twilight Princess
Portal 2
New Super Mario Bros. Wii
Donkey Kong Country
Super Mario World
Wow, I have a lot of favorite games.