There seem to be more and more choices when it comes to self-publishing appearing all the time. I thought I'd give a bit of an opinion on my own experiences with just a few of them.
Blurb.com
This is the company that I've used the most, using them to print and then publish my large-format travel books for almost twenty years. The quality is amazing, the printing times are short and the service, if you ever have an issue, is second-to-none. They offer excellent software with their own Bookwright and a range of templates and plug-ins for Adobe products. You do, however, pay for the quality and the support with relatively expensive per-page and per-book rates. Distribution seems to work well, but coverage is spotty.
Lulu.com
I moved towards Lulu to start to publish more readable paperbacks. The pricing was one of the major factors in the decision. Print quality is good, turn-around is reasonable and document preparation is fairly painless. Simply producing a final PDF file from a word document is enough for the interior and then you just add a cover from the calculated sizes provided. If you choose to use distribution, you can set a retail price and your book appears on Amazon and other bookshops across the world. By more modern competitive standards, the prices are somewhere in the middle and distribution costs push the final retail price, even for a simple paperback, quite high.
Amazon (Kindle Direct Publishing)
I'm still very new to this one, even though I signed up several years ago. I've now published my first novel using this service and it's been a pretty polished experience so far. It's too early to tell how well sales are managed, but the rest of the process is pretty much flawless. They encourage you to make your book available in all three formats, Kindle, Paperback and Hardback. This is made as simple and painless as possible with a mixture of their own software for Kindle publishing and simple PDF uploads for everything else. Print prices, despite upcoming increases, are the cheapest I've seen and turn-around times are fast.
Distribution and management is simple, they even allow you to pull together work published elsewhere. You can take advantage of their Kindle Unlimited reading program if you wish and they don't stop you publishing elsewhere. They even offer cost-priced author purchases.
Quality Comparisons
Here are the two proof copies of my first novel. The Amazon one is on the left, with the proof bar across it. Sizing issues with the cover are my fault. There really isn't much to tell between them, when it comes to the process and the quality of the final product.
Here are the insides, Amazon on top and Lulu below. I actually prefer the Amazon output just a tiny bit. The graphical header is slightly darker and more defined, but again there's very little to tell between the two, particularly in a photo. Paper quality is similar for both, a little thin, but acceptable for an inexpensive product. In both cases, the reproduction of my original file is pretty much spot-on. Text is clear and very readable for both.
My Recommendation
Well, unless you have an aversion to the Bezos Empire, then I think I'd go with Amazon from now on. I'm toying with the idea of a colour project for release at the end of the summer. Maybe then will be a good time to revisit this subject and take a closer look at the quality and the experience.