I don't know the original source for all these, but I'll bet money that the Stainless Steel Rat ones are all Audible recordings, as one of them is and they're all read by the same chap. The Deathworld one comes from Librivox, but I've trimmed out all the really annoying announcements and ads. There are two versions of the first Stainless Steel Rat books, but they appear to be identical apart from the files being split differently - I thought I'd just include both to give you a choice. Oh and you probably all know that "Make Room Make Room" was filmed as Soylent Green.

Bill the Galactic Hero (BBC Radio 4 production)
Deathworld (trimmed Librivox edition)
Harry Harrison - Stainless Steel Rat - Book 01 - Stainless Steel Rat
Harry Harrison - Stainless Steel Rat - Book 01 - Stainless Steel Rat (alternative version)
Harry Harrison - Stainless Steel Rat - Book 05 - Stainless Steel Rat For President
Harry Harrison - Stainless Steel Rat - Book 06 - A Stainless Steel Rat is Born
Harry Harrison - Stainless Steel Rat - Book 08 - The Stainless Steel Rat Sings The Blues
Harry Harrison - Stainless Steel Rat - Book 10 - The Stainless Steel Rat Goes to Hell
Harry Harrison - Stainless Steel Rat - Book 11 - The Stainless Steel Rat Joins The Circus
Make Room Make Room
Stainless Steel Visions