I try them all.
There is one that Qualipet sell, but it has been re-branded. It's now called BioKat. You can get it in 20kg bags. This stuff is good.
Since one of my cats died (RIP Pussolini) - The other one doesn't generate as much and I use Catsan. I now use a mixture of the two which works really well.
I also use something similar to this. The boys love to kick up a storm inside the box and litter would otherwise go everywhere. Also, they sometimes can't be bothered (or maybe it's just fun to watch me clean it up) but they have been known to think/shit outside the box.
I also use thick plastic liners. These are marvelous. The boys don't scratch them and it makes removing the chunks easy. Just lift the sand from side to side by lifting the plastic liner. All the chunks roll to the top for easy retrieval.