Personally I prefer Fitch
It works out cheaper and I've been using it for years. I have tried Kaytee Clean and Cosy. It is similar to Fitch but the coloured ones have a bit of a smell - although it does wear off if aired. I just prefer the texture of Fitch. I am not keen on Carefresh as found it had a fine dust but many people happily use it. Both Fitch and Kaytee CC are dust free really. But Kaytee works out a lot more expensive than Fitch and I have two 100cm cages so prefer to buy the Fitch in bulk.