I love watching the fish interact in a really interesting environment:
A big rubber Rancor monster lurking behind/through some plants, a lot of agates, quartz, and other found rocks, a huge rock from the front yard, two old fired clay sculptures I made in high school (one with a air stone in it that I turn on sporadically), a fake bonzai tree that actually works well, a geode (under the bonzai) a half-buried Terminator robot, some African rootwood, a plasteresque gargoyle statue barely visible, and a whole ton of mostly good-looking fake plants, coming from below and above (some from the craft store which are the best looking and yet cheapest of the bunch ... will play with some real plants once I get my tank fully stocked with fish).
Watching the tiger barbs swim in and out of the Rancor's mouth, and sometimes peck at his teeth as though cleaning them, is pretty ####in cool.