Lizard Activity Levels?

Im thinking about getting a new lizard that would do well with live plants and prefers a little bit of climbing. I am thinking of a crested gecko, because its nocturnal so the lighting is a little easier, but generally id like a few other suggestions. I have an exo terra 18x18x24 gl terrarium with live plants that was build with a crested gecko in mind but the plants are pretty standard and i was just wondering what other animals would do well in a cage this size. if you could explain the activity levels of some possibilities thatd be great too. so any help would be appreciated.