Say what you like. Master of Orion II is the best 4X game ever created, and easily the best sci-fi game in the genre as well.
As for SMAC... While the game did a lot right, especially with the handling of factions, overall, I prefer the mechanics of the Civilization games. If I had a choice of which to play, I'd go back to Civilization II Fantastic Worlds over SMAC. I just prefer the gameplay. Maybe it was because I'd played so many Civilization games before, but the changes to building and colony control just really felt off to me.