Dragon Warrior/Quest on the NES. Played the heck out of it, but never could get past the third or fourth bridge. Mostly because I was 6 or 7 years old and didn't understand about gaining money to get better equipment. And the game is one of the harder early RPGs. I eventually learned about getting better weapons...but just still walked too far and got my butt handed to me by Druids and Skeleton Knights because I didn't know where to go. Ended up hating the game.
Funny, because then about 10-11 years later I played Dragon Quest VIII and now the series is one of my three favorite RPG series ever. Partially because its got a higher level of difficulty and because its got a lot a depth in the gameplay. I just couldn't find it when I was 6 years old and wanted to play Zelda and Duck Hunt.
Edit: This may have come before or after some REALLY old Early PC RPG I played at a friends house. All I can remember is it was based off Snow White, and you mostly just answered questions to progress. Then you could collect items and cast spells at times to defeat random obstacles in your path. Really loosely based on Snow White I guess... No idea what the game was called.
Six upcoming games you should look into:
