All righty, let me give this a shot:
WRPGs:
Diablo series - A lot of good isometric RPGs out there, but this still rules them all.
Fallout series - Starts off on isometric, and they're great, but the third part of the series is probably the best thing Bethesda ever managed to make.
KOTOR series - When I'd lost all faith in LucasArts, I was still able to enjoy this, since you can always rely on BioWare for a solid, if not great, RPG.
The first Deus Ex - None of the following property.
Quest for Glory Series - Old? You bet your ass. Prepare for some typing. But still one of the best, silliest RPG series out there.
JRPGs:
I'm on board with a lot of the JRPG bashing, but they are with redeeming games, and I can allow myself to get engrossed in them all the same.
Dark Cloud 2 - The first had a bunch of problems, and DC2 fixed them all. Action-based combat, great weapon system, neither protagonist is androgynous, a lot of minigames that actually assist with the game without being so mind-numbing as to detract from it.
Disgaea - Do not play this. I liked it, it's on my list, but I can't imagine anyone really caring about this series unless they are completely enamoured of the concept of level grinding.
Final Fantasy VI and VII - Admittedly, these may be on my list because I didn't know any better when I played them and now they live inside a cocoon of nostalgia. That being said, this was Squaresoft when I liked them: bizarre, anachronistic worlds with interesting design aesthetics and no half-assed American voice acting.
Demon's Souls - Yeah, OK, the game is relentlessly difficult, and this was a pretty recent release, but it's merciless head-stomping good fun with a beautiful world that you don't get enough time to enjoy, what with the constant dying and all.
Mario RPGs - Be they Paper Mario, Mario RPG, or the Mario and Luigi series, the Mario RPGs have always been a bright spot in the vast wasteland of contrived, poorly-executed JRPGs;