Pros: smells nice, natural, organic, biodegradable, flushable
Cons: needs to be replaced when it breaks down
We used to use Feline Pine in our cats' litterbox, and I liked the stuff. It smells quite nice - like pine trees. It's also 100% natural, organic, biodegradable, and flushable, although I recall reading that you're not supposed to flush cat poop.
Anyway it's nice stuff, and not too expensive. It comes in little cylindrical pine pellets. The only problem is that after a bit of use and scooping, the pellets tend to break down and get wet pretty easily, and then you have to replace the whole litterbox full of damp pine stuff. I think the pine litterbox lifetime is pretty comparable to your cheap silica-type litters.
This is probably my favorite cat litter, and I've also used the newspaper kind and the normal cheap silica type stuff. Feline Pine works well and smells good, which is especially helpful when dealing with stinky cat poop!