199? - 1995 or sofactory manual - Invaluable for old part numbers. I use it all of the time. Not great if you are not a mechanic.
1999 or so - Pink Cover Factory workbook - Very rare. It has some items that the 1995(?) to 2004) factory shop manual did not have. Having both of them covers a lot of territory. Not good if you are newbie
Iron Barrel manual by Snidel - Good reference book, his best work on the RE.
Best Iron Barrel Manual Has some bad info but it is so limited I am not even going to mention it. It won't get anyone in trouble if they take it.
About 2006 or so (AVL manuals) the factory manuals started to improve markedly. Much better and more pictures better specs and better explanations. One thing you have to watch with all of the AVL and UCE factory books is that not all of them have the engine stuff in them. For example the original UCE book had the engine in it, Then when the later UCE and GT manuals came out they did not include an engine section because it had already been published it. Don't understand why.
UCE manuals are the best yet. I collect shop manuals of all types and they are good. In most cases with all shop manuals there is data that you might like to have more clearly stated. When I start in on any vintage car I always buy as many differnt manuals as I can. What one doesn't cover the next usually will.
The later Snidal manuals are "in theory only". Pete does not have a UCE so they are written at a distance