Coolest fish tank accessories?

[Roz_26]

What are the best fish tank accessories? Something I might not have heard of like special lights and stuff?

 

[reeeiegene]

well, i heard that there's this new submerged lighting, it's shaped like a disco ball and it radiates uh... well... disco ball lights.... kinda weird...

personally i don't like artificial accesories, plants and rocks are much better