OK, leaving EB out of the equation, I guess these have had more replays than anything else, might not be in order after the first few:
1) Pool Of Radiance (original Gold Box) think I bought 4 versions of it, C-64, Amiga, and 2 PC collections with it in. (C-64 still sounds the best, really belts out the intro tune!)
2) UltimaV: 3 copies - C-64, Amiga and PC. Never tire of playing.
3) Moria: Amiga, very nice Nethack/Rogue clone.
4) Ancient Domains of Mystery (ADOM) : so involving.
5) MM3. although World of Xeen catching up fast.
6) Lords of Midnight - C64: OK, bit of a hybrid wargame with some RPG elements, but the cause of so many all-nighters! An early classic.
7) Knights of Legend: C-64 and later found abandonware PC version. For all its bugs, and unfinished state, the basis of a very good game was in here, even with the constant switching disks on the Commodore!
probably Ultima IX: A real treat for the eyes, probably let down by bugs and seemingly rushed finish to it, and support dried up literally at release, as all resources got shifted to Ultima Online. Even so, still an excellent game, would love to have seen Origin carry on and produce another in the same style.
9) Phantasie III: Ok, it looks awful today, but for its time, very appealing.
10) Realms of Arkania - Blade of Destiny: I tried so hard to like this, the ideas within, and just the sheer size of it, it appeared to be a fantastically well-thought out RPG. But, I found too much within it seemed to be filler, so many houses/residents that didn`t interact, some horrible bugs, and a plot that seemed to disappear part way through the game. The early "Ship of Death" quest didn`t always materialise, and being so early, couldn`t always be completed fully with a starting character. Perhaps I was really unlucky with a bad copy, but to almost have a fantastic game at my fingertips, very exasperating.
Well, that`s 10, although so many more come to mind, many of which should be in the 10, but I tried to use just 1 from each series.
All the Ultimas rock, as do the Gold Box SSI games (although the last ones in 2 of the series, Pools of Darkness and Dark Queen of Krynn just didn`t push the buttons like their predecessors).
Buck Rogers was fun, newer games like Baldie`s Gate, Icewind Dale, Pool of Radiance (revisited), NWN, and Oblivion, probably will stand up well, if I ever find the time to play them fully.
Classics like Rogue, Nethack always appeal, as do some of the old `adventure` genre, like Colossal Cave, Zork, and the Scott Adams games, as do games like King`s Bounty (both old and new).
Again, time has never been on my side where the online RPGs are concerned, still got Ultima Online waiting to be tried, and a few others like Guild Wars.