Hey, thanks so much for your responses!
OK, based on the info you have provided, I've formulated what seems to me an optimal approach (see what you think):
1. As I said, I already own the four iPad titles [Avadon I and II, Avernum: Escape, and Avernum 6 (!)]], so it makes sense to play those on the iPad (probably Avernum: Escape, then Avadon I, then Avernum II [which should be out later this year], then Avadon II, etc.)
2. On the MAC, it looks like Nethergate: Resurrection first, then on to/through the Geneforge series.
3. If I've still got the "bug" after playing through these, I may even dip into "Blades of Exile" and/or "Blades of Avernum."
So are all of the games part of the same narrative world, or do each of the various series take place in their own unique "universe"?
Also, are there other series of a similar ilk (i.e. classic RPG) that you would recommend for the MAC or the iPad? (I'm already into Baldur's Gate I and II on the iPad.)
Rob