1.

The Legend of Zelda. My favourite game series of all time. Not even counting the, IMO, consistent master quality of these games for such a long running franchise (Excluding CDI, of course), the Legend of Zelda easily makes up about a good 30-40% of my childhood. Majora's Mask is my favourite game of all time. I will cherish this series always.
2.

Metal Gear. The zany and lovable characters; the wacky combination of science, technology the military and.... anime? XD; the insane, yet thought provoking story; the 4th wall breaks; the surprisingly deep gameplay (Especially in MGS 3,4 and 5) and of course, the inside jokes and memes. Metal Gear checks off all the right boxes for me.
3.

Fire Emblem. I first experienced Fire Emblem at a friend's house back around the time leading up to Brawl's release. The game in question was Path of Radiance. I was really intrigued by the game play, as I had never seen a game quite like it before. My friend let me borrow it for a couple weeks, and I instantly fell in love with the game. I love planning things out in real life, so Fire Emblem game play definitely complimented that love, what with its focus on preparation and strategy. (Funny enough, Ike was revealed as a newcomer in Brawl literally two days after I first played PoR, so that was pretty cool. Got spoiled on Ragnell though. XD )
Since then, I've played every Fire Emblem game and have loved pretty much all of them. Radiant Dawn is in my top 10 favourite games of all time, and Ike is now one of my favourite game characters of all time.