Was really surprised I had to scroll down so far to see Carcassone mentioned.
Some of the things I love about it include pretty much guaranteed gameplay time: amenable to beginners and experts; easy to explain; multiple strategies available; good blend of luck and strategy; interesting expansions; and more that will likely think of later.
Mom was in her 80s when I introduced her to Carcassone and she got good quick.
Leaving it with my ex was one of my few regrets about the divorce. :-)
