To the question about PSX emulator quality... yes, the graphics are better than the PC version. My understanding is that (especially with the later PSX games) the textures they used were large and detailed, but were overly pixelated due to lack of hardware rendering and low resolution. So... when you slap it in your PC and load up ePSXe, your GeForce/Radeon goes through and renders the pretty textures in 1024x768 - 1600x1200 res and... ta-da! Aesthetically pleasing PSX games. FF7 doesn't really gain much from being played on an emu due to the lack of textured polygons (garauded shading? is that how it's spelled? ...anyway...) but games like Chrono Cross and FF9 show noticable improvements, as well as the GEARs in Xenogears.
As for the best RPG debate... I get torn between FF6, 7 and Chrono Trigger. FF6 because it was pretty epic for it's time and the sentimental factor... FF7 because of all the games it attached me more to the characters (like a previous poster, I seriously was so depressed when Aeris died) and Chrono Trigger because... well it was just a really badass game. Xenogears deserves honorable mention cause the story rocked, and the combat system was hella tight, but the second disc was SUCH a letdown.