I also have the ABC Amber CHM Converter and what I like about it is that you can convert CHM to many different formats -- RTF, HTML, DOC, TXT, PDF, PDB. I think there are about 20 available formats in all.
The freeware LIT converter has gotten a good workout here but the most used freeware converter from ABC Amber for me has been the Palm Converter as I had a large stock of PDB files that I have converted to the Sony Reader.
I have purchased quite a number of converters from them in the past and found them to be excellent value for the money. I should note for the record that I have no stake in the company and am just a customer.