During last week I managed to play only some card games (or games, based mainly on cards) but I'm still happy, all of those 2-player sessions have been great experiences.

Ascension is my all time most played game (when playing all the expansions as standalone games as I do) but I still find it fascinating. Storm of Souls this time. Best with 2p, I'd say. It's playable with 4 as well but in that case more experienced players may have too big downtime when beginners discover all the combos etc. Avoid playing it with more than 4, though.

Tried also Ghost Stories again, with 2 players, just the base game. If you're feeling that everything seems to go according to plan - well, things will change soon :) I don't remember if we have ever won the base game. Yes, there are guides available in BGG... but it's somehow like... playing some FPS 'godmode' with unlimited ammo/health. No challenge, youknow :)

And finally something quite forgotten... 7 Wonders. Damn, this shines with 2 players! If there are more players I have never enough time to watch who has what developments etc - but this way it has more suitable pace. And of course operating 50% of time in behalf of the "dummy player" - it's just extra fun. Leaders expansion just doubles it. Waiting eagerly for Cities.