Hard for me to say.
I'm pretty new to this genre. I grew up on JRPGs, but always wanted to sink my teeth into a long juicy, CRPG.
So I bought a bunch from GOG.
Might & Magic VI isn't grid-based, but it's still one of the best western CRPGs I've ever played in my life. I didn't take to Might & Magic VII, surprisingly. I guess spending 150+ hours on VI burned me out.
Lands of Lore is great, and far more accessible than many other games in this genre, which I liked, but I actually fell into a trap many hours into the game that would've forced me to lose two hours of gameplay. I got impatient and haven't touched it since.
Still, I think I'd have to say the older
Might & Magic games and especially
Wizardry I are my favorites. Haven't beaten any of them yet, though.
What makes Might & Magic so great is that
it's a game first, and a realistic medieval fantasy survival simulator second. Might & Magic, especially the older ones, have just the right amount of depth and accessibility. The gameplay is fast, fun and whacky without being stupid. The simulation elements aren't tacked on - they're integral to the core gameplay - and aren't so overcomplicated that I felt bogged down by them. I like that!
Realms of Arkania is a good effort, but I feel The Dark Eye system is tacked on and just overcomplicates things. It's different from how Baldur's Gate, for example, uses the AD&D system. In Baldur's Gate, the AD&D system was reworked into the core gameplay; it laid down a solid foundation for Baldur's Gate's gameplay. In RoA, however, it feels like they used The Dark Eye system just because they could, not because it enhanced the gameplay or gave them a foundation upon which to build something great.
Unnecessary depth - that is, depth that isn't a part of the core gameplay - or depth that isn't put to any use, is how I define "overcomplicated".
Ishar is good - reminds me a lot of Might & Magic, but I feel Might & Magic had a better balance of turn-based and real time elements. Ishar becomes a frantic exercise in button mashing. Still great, though. The open world exploration feels very Metroid-like somehow.
I have not played EotB, but I desperately want to. I'm hoping, praying, it comes to GOG, but I know that there are issues with the D&D license and Atari, so I won't count on it.
I'd like to see Wizardry on GOG too, as I haven't played much in the way of them either, and I feel they are probably some of the best overall, especially after playing Jagged Alliance and getting a feel for how skilled these developers are.
Wizardry is now owned by some Japanese company, though, so fat chance of that happening. Ugh. Sigh.
Oh well.
So far the winner is Might & Magic for me by a pretty wide margin. It's like the DOOM of CRPGs. They just did everything right.