Pokémon Blue.
So simple yet so many options for how to raise your party, albeit on a strictly linear path, but it's an original Game Boy game. What else would you expect?
it got me started in my interest in JRPGs. I then later on played Final Fantasy VIII (which I prefer to VII, yes I'm scum) and absolutely loved that, and a lot of others in that series, and also tried a few other JRPGs.
In Terms of WRPGs, I got to that party a bit late. My 1st was Fable. I loved it. Simple as that. I didn't play anymore WRPGs until the current gen, when I got to experience Mass Effect, Fable II, and Fallout 3. Love those games!!