Many may think I'm a dork for lking this sort of stuff but I have been attracted to this since I was around 10.
RPGs apparently started with the advent of Dungeons and Dragons (D&D) and when the computer became common for personal use, text-based stories were made, as well as networked (internetworked now) MUDs or multi user dungeons.
When graphics got better, like Nintendo better, prettier 8 bit graphics were integrated with the texts and one could travel around the countryside, fight monsters, collect gold and "experience"
(which makes the character stronger and lets them usually learn spells and skills).
They could also go to towns and castles and talk to people, later on more detailed conversations could happen.
Famous RPGs from that era were the first Dragon Warrior games, the first Final Fantasy, and of course the beginning of the Legend Of Zelda series.
As the Super NES was big they had many ground breaking RPGs, the sequels to Final Fantasy were huge, as they had a much convoluted plot, as would all good RPGs afterwards.
Also big were Secret Of Mana, Chrono Trigger, and on the Sega Genesis system, the Phantasy Star series.
When the newer systems came out in 1995, Sony's Playstation became the system to feature many RPGs, and Square, who makes Final Fantasy and other great RPGs, got away from Nintendo for good and made games only for Sony.
In 1997 Final Fantasy 7 made RPGs become mainstream so I won't seem like such a geek liking them, but it made the "new school" style of RPG as compared to the "old school".
FF7 used many computer cut scenes (as did it's sequels) and it had extremely detailed characters, in appearance and in background both, sad scenes like the killing of the main heroine by the main villain could make a tough man like me cry, the music also was better than anything before it.
RPGs exploded afterwards again, too much info for me to describe here, look at a real website for that :=)
I will tell you the game Xenogears is a must buy even if you don't like RPGs because I never have played a game with such a complex storyline and plot, even some books aren't as good as this, and its main topics include religion and God, theology and philosophy.
Here's a few links about RPGs in general, individual RPGs, and video games in general
Game Spot, reviews of many games
Gamestop, where you can buy any game
Video Game music archive, check out the songs to the Final Fantasy games, FF7 especially.
Game Faqs, information, secrets, codes, walkthroughs, and reviews of all games