We have a wider circle of friends who are boardgame enthusiasts, so we go through a rather lot of them. Some stick, some don't. These we play regularly and have a lot of fun:
There are more that made an impression on me, I remember playing them a few times, but do not want to play them again (Do you know that feeling? :D ), eg. Eclipse (the galaxy-wide battle 4X preparation-takes-as-long-as-playing-and-playing-takes-a-whole-day strategy), Agricola, Mice and Mystics...
Go is the most amazing game I know. I often regret not sticking with it as a kid. And IRL games are wonderful. The feeling of the stones on fingertips, the rattle of prisoners, the clicks and clacks when placing stones on the goban...