For my first ever post on this forum, I submit to you this list. Note: I love tactical RPG's the most, so my console picks will probably be weighted more heavily towards that subgenre than a lot of people's.
NES: I guess FF1? Not a lot of real RPG's yet, even FF1 I can hardly play, way too much grinding and the battles take forever.
Genesis:
Shadowrun
Shining Force 1 and 2
Phantasy Star 4
SNES:
Earthbound
Ogre Battle
7th Saga - lot of grinding but pretty quick battles so I like it)
FF6 - duh, the best in the series except for my personal pet favorite Tactics)
Illusion of Gaia? Barely counts as an RPG I guess but I liked it a lot.
Super Mario RPG - Can't believe nobody has mentioned it, really? Nobody else likes it?
Fire Emblem 4 - The whole series by and large is great but 4 is really the stand out IMO.
PSX:
Valkyrie Profile - probably one of my top 5 games of all time
FF Tactics
Breath of Fire 3
Suikoden 1 & 2 - Suikoden 2 probably my all time favorite console game
Chrono Cross - I liked it more than Trigger, I know I'm in the minority on that though
Legend of Mana - Liked it more than Secret of Mana, I guess I'm just a rebel
Lunar and Lunar 2 - gameplay wise very much typical jRPG but for some reason I just fell in love with the characters and stories in these 2.
Saga Frontier 1 - Interesting game... maybe not the most "fun" in the strictest sense but something about it just makes me feel like I have to list it.
Vagrant Story
Brigandine
Tactics Ogre
PS2:
Dark Cloud - I know it's not a real popular one but I really dig it
Suikoden 3 and 5 - My continuing love for Suikoden, 4 not withstanding which was terrible.
Suikoden Tactics - WAY better than 4, from whence the characters in it came
Dynasty Tactics games - Again these scarcely qualify as RPG's but I'm admittedly casting a pretty wide net here.
Front Mission 4 - I haven't played the others in this series but this one is really cool
PS3:
Well... Valkyria Chronicles was awesome. TBH the vast majority of my gaming now is done on PC, I grew up with consoles but graduated to the superior system. My PS3 mostly gets used for Rock Band now.
PC:
Baldur's Gate 1 and 2
Vampire Bloodlines - Probably beaten this game from beginning to end more than any other game ever
Witcher
Morrowind
Fallout. 1 and 2 were the best, New Vegas was pretty good, even 3 was acceptable, though nowhere near the first two. I also like Fallout Tactics, it's an underrated entry in the series IMO, People expecting it to be Fallout 2.5 were disappointed but taken for what it is it's a very good game.
Deus Ex - Too bad the second one was such a tragedy of errors
And if we are allowing for Diablo style games:
Diablo 1 and 2 - Obvious
Titan Quest - Very good game that doesn't get mentioned nearly enough. Awesome class system with awesome story and greek mythology, there is no way to lose with this formula.
I'm sure there a ton that I'm missing but I've been typing this for ages and I'm done.