I can't really comment about the Avernum series, but the Geneforge games are definitely self-contained (they're also much more original and interesting than the Avernum ones imo, but that's beside the point).

I played Geneforge 5 first, and I liked it a lot, enough to buy the other 4 games in the series, each of which have their strong points, though none were quite as good as the 5th.

I tried Avernum 1-3 but i could not get past the interface to enjoy the game. Avernum 4 is considered by some to be one of the weaker installments in the series, too combat heavy with a story that is lacking. I am still playing it and loving it.

Avernum 6 is where i picked up the series and it is a fantastic game. Huge game world with some great descriptive text and welcome humour. Lot's of choice with how to develop your heroes and very nice graphics and spell effects. Some tough battles that will remind you of ToEE :) Everything about number 6 is clear and crisp, loads of quests and freedom. If you have an afternoon free, you can really lose yourself in that game. No music is the only negative i can think of, but then Jeff's games never have any other than the title screen.

Definitely check out Geneforge 5 though before or if you make a purchase. Another excellent game.

For anyone still looking to try this series but are put off by the graphics it looks like he is rewriting the original using his newer engine http://www.avernum.com/avernum/index.html

Well the old Avernum was already a remake of Exile, so this one is a remake of a remake. :p

I liked the technical improvements made in Avadon, so this might be interesting.
I just hope Jeff doesn't make it more linear and "streamlined" like Avadon was in terms of gameplay.

Ive had mixed feelings with spiderweb's games. The only game I can play and enjoy casually is avadon. Avadon had a great story, better imo than the other games, cool characters, classes, felt like d and d.

Ive played avernum 1-6 and gene forge 1-5 and never had a good experience with either series. The avernum series was never really interesting. The gene forge series however, was interesting, but incredibly difficult past 40% of the game. Ive never been able to make it past that point in any of the gene forge games.

I would say that jeff's got a lot to work on. For now, I'm glad that avadon is his interest though as it shows he can make a game that anyone can enjoy. Hopefully his series in the future will be like that. Plus its like bg and ps torment, how can you beat that?

I have a Steam Key for Avernum 4, 5, 6

Im open to any trade offer.