I've been a gamer for as long as I can remember. My first game I can remember playing was Boy and his Blob and although it wasn't the most enjoyable experience (try figuring out what every single damn jelly bean does when you're 3-4 years of age), it piqued my interest in video games at a very early age.
My first favorite game was Super Mario Bros. 3. I missed out on the first two games, but made up for it with this great example of no-nonsense game play. You really felt you were Mario soaring through the air, swimming through the water, and unleashing hell in a Kuribo's Shoe. It will always be one of my favorites and it reinforces my love of all that is good and pure in video games.
Super Mario World was also a very special game for me, and arguably my favorite game of all time (competing with Majora's Mask, Mega Man X, and Warcraft 3). Another perfect example of no-nonsense game play and fantastic artistic design. It was one of the most graphically enjoyable games of it's time and it's still a beautiful game in this day and age.
Some other notable games that I thoroughly enjoyed:
NES: Excitebike, Mega Man 2-4, Micro Machines, Blades of Steel, Battle Toads and some more I cannot remember (I missed the vast majority of the NES generation, sadly)
SNES: Mega Man X 2/3, Super Mario World 2: Yoshi's Island, Super Mario Kart, Uniracers, Star Fox, LoZ: A Link to the Past, Mega Man Soccer, Final Fantasy VI, Darius Twin, Super Mario RPG, Chrono Trigger, EarthBound, Ken Griffey Jr. Presents Major League Baseball, and many others.
N64 (noticing a pattern?): Super Mario 64, Super Smash Bros., Star Fox 64, Mario Kart 64, Mario Tennis / Golf / Party, Excitebike 64, Donkey Kong 64, LoZ: Ocarina of Time, Banjo Kazooie, Banjo Tooie, and more
PS2: Too many.
PC: Ditto.
Running low on time so I'll fill this out later.
For the past five years or so, I've been playing Defense of the Ancients with a few breaks here and there. This game brings out two of my favorite things to think and talk about; character design and PvP balance. This unofficial map for Warcraft 3 has a staggering 91 unique characters to choose from, each of them effective in their own right (although some are more powerful than others, it doesn't matter much in public games). Finding out the subtle nuiances of each hero, effective item builds (there are a LOT of items you can choose from), and hero combos (two teams of up to five heroes per team) is something that keeps me coming back for more. On top of all that, the actual gameplay is fast paced and energetic.
The game Demi Gods is supposedly based on the same type of gameplay, so I hope they get the balance right when it launches. Looks promising!