Matrix is one I like to use.
One which I am getting ready to try out is a block type item made of what I believe is essentially the same material but looks like a square brick. It is called Marine Pure High Performance Biofilter Media for SW
The block I got is the larger one 8"x8" block 4" thick. Has 23,000 square feet of surface, an amazing amount. I want to get one for my patio pond too.
Any how I also have ceramic media rings of several manufacturers and sponge. Like the media in the AquaClear filters, with Purigen for the HOB
In my Canisters I run Matrix and rings some solid pellet ones and some old bulk pad because they were seeded with BB, with plastic stars - API Bio-Chem Stars. I like them!!! They are an advantage over bioballs because the star shape keeps them almost free of buildup. Also they really allow water flow because of the shape and way they seem to angle when dumped into the basket.
Overall the least favorite is bioballs because they really trap gunk, then the ceramic rings because they do catch gunk in the centers as well and seem to compact more, maybe I just pack them in too much. :/
A prefilter sponge is great and lets you catch lots of gunk before going into the filter system and is usually a quick rinse in pwc
Usually pack in as much media as I can and still get good flow.
And Purigen. Love that stuff too.