Julius and I spend some time taking a tour of the world of the 18 Card Microgame.  This neat little sub-genre is full of all sorts of neat little games.  These games are usually quick playing and often very creative.
(10:10) Sprawlopolis (BGG, Button Shy)
(15:00) Banned Books (BGG, Button Shy)
(17:38) Ragemore (BGG, Button Shy)
(19:39) Pentaquark (BGG, Button Shy)
(24:18) Twins Stars I (BGG, Button Shy) & Twin Stars II (BGG, Button Shy)
(26:40) SpaceShipped (BGG, Button Shy)
(29:30) King's Gambit (BGG, Gamecrafter)

I went looking for references to 18 card microgrames for solo play but didn't find anything specific.  Time to go make a geeklist...
Solo Playable 18 Card Microgames