I bought Star Realms ages ago after all the hype about how it's an amazing 2-player game but never got a chance to play it. I'm quite slow to learn rules on my own without playing and after spending ages to set it up my wife took one look at the space battle theme said, "I don't think this will be my kind of game," so I had to put it away. I got to play it a couple of times on holiday a few weeks ago with my brother-in-law and it seemed like it would eventually be a lot of fun, what with the alliance powers and defensive outposts but we were still learning it. Don't reckon I'll get another chance to play it for a year now, though.
Instead, I can recommend a quick card game called Coloretto that is good for all the family. All you have to do is collect three sets of the same colour, which you decide at the end of the round, but any further sets of other colours you possess are deducted from your score. Played it lots this summer. I bought the German version because it was cheaper and there is no text in the game, just coloured cards. The rules are available online.
I also got out Munchkin Booty, which was still sealed, and my family took one look at it, realised what it was and said, "Oh it's that game that doesn't make any sense," before shelving it so I've still to play it.