I'm getting such a kick out of reading all of these! I figure I can do mine. These aren't in any particular order, except for the last one.
Breath of Fire: My very first RPG. You never forget your first, am I right? I received it as a birthday gift from a friend of mine when I turned ten. Prior to this, I played the Marios and the Mega Mans and the Sonics and so on, but Breath of Fire just flabbergasted me. The game wasn't over in an afternoon! The game had a story with lots of dialogue! The game had two fierce female characters that I could use in battle! Breath of Fire started my love for the RPG genre.
Mega Man X: Of course, before I even heard of Breath of Fire, I was playing Mega Man X once a day. We received a Super Nintendo as a Christmas present and everyone received one game along with it. Mine was Mega Man X and...I can still play this game like a boss. I wish Capcom would get their **** together and make a Mega Man X9 already.
Chrono Trigger: Yep. Not much to say that hasn't already been said. This game rocks and is still easy to pick up and play.
Kirby Super Star: This was a wonderful game that made me wish for a four player multi-tap. Since the game was two-players, my siblings would always argue over who got to play the helper. There were so many great memories from Spring Breeze all the way to The Arena.
Secret of Mana: This was -THE- game that defined my childhood because it combined action, adventure, and RPG elements into one fantastic cartridge. All of this, combined with the gorgeous presentation and soundtrack make it my number one pick. Whether I was playing it by myself or playing it with a friend or family member, I always enjoyed going through this game. Like Chrono Trigger, I have no problems popping it back in these days.
Honorable Mentions: Mega Man X3, Mega Man 3, Mario 3 and Final Fantasy II (IV).