Magic : The Gathering's single player option called Shandalar.
I would buy this for sure if it ever came to GOG.

If you haven't already, you should take a look at Etherlords. It's got the feel of MtG, and isnt a bad game at all.

This is the place for those types of discussions and voting: http://www.gog.com/wishlist/games/magic_the_gathering_shandalar

P.S. Of course, you're always welcome to discuss here, too!

Sometimes I wonder if people were playing a different copy of this than I was. I found the mandatory ante system to be absolutely game breaking as if you didn't win the first couple encounters you were pretty much screwed and the opponents were very tough early on.

.............

While the Etherlords games are definitely good and worth recommending I would also like to have the old MtG game from Microprose here. It is still better than any other MtG computer game that has come out since then.

Sadly that game had some issues on newer CPUs and would often just hang for no apparent reason on newer computers or I would still be playing it. :-(

But if the legal hurdles in re-releasing it could be cleared and GOG's reverse engineering team can work their magic on it, I'd buy that game again from GOG.