For me the best RPGs of all times are the old ones, out of nostalgia, although newer ones surpass them in many ways. Namely that's Ultima 6, as I spent hours and days just to make this game run on my Amiga (one of the disks had an error, couldn't find a replacement copy, took me long until I actually find out that LB wants to know something from the manual as a copy protection, etc...). And as second the AD&D RPGs from SSI, especially Pools Of Darkness. The other SSI games were mainly crap, but I loved them anyway.