Avernum seems iffy. Geneforge titles (from the same company) are quite excellent though.
So there’s another series of games that I can play after the Avernum set, that you consider even better?
:head explodes:
So essentially, Spiderweb Software has provided me with all the computer gaming I need for the next couple of years.
SWEET!
Does someone remember the name of some computer RPG where you begin the game in a spacecraft that crashes on a fantasy-style planet, where you’re welcomed by friendly bipedal big cats? I remember having quite enjoyed it.
And what about this other oldie I barely remember now where you begin escorting a prisoner, tracked down by assassins? Does it ring a bell to somebody?
As for Might and Magic VI, IMO, it was an acceptably good RPG but not outstanding. Quite a lot of dungeon crawling, a lot of critters to kill every time you move, and the storyline wasn’t particularly impressive. The funniest part IMO was mixing stuff at random to prepare potions that would explode at your face half the time.
Might and Magic VII was pretty similar, especially the storyline. Maybe slightly better because you owned this castle and, IIRC, could pick up a side when events were unfolding.
Since I played both to the end, I can’t tell they are bad, just so-so. But on the other hand the OP already played all the RPGs I really liked, so it’s not like I could give a better advice.
Betrayal at Krondor? I guess it could be a lot of things, but that seems to apply. The prisoner is freed after the first attempt and becomes a party member.
I’d recommend Heroes of Might & Magic 2-5 (different than regular Might & Magic), or Albion.
Albion is a fairly older game that’s a little quirky and sci-fi/fantasy-ish, but I enjoyed it.
Wiki info for Albion. Not sure how easy it is to find, and I can’t for the life of me remember where I originally procured it, though.
I didn’t see your post before I mentioned it, but it’s ‘Albion’. 
I just mentioned in in the post above this one.
Home of The Underdogs has it, or at least that’s where I got it from a couple years ago.
You guessed right. I checked on wikipedia and it’s the game I was thinking about. It seems to me I enjoyed it, though my memory of it is too blurry to actually advise it.