It's great to have a nicely laid out PDF file for your tablet. It's even nicer to have a dead tree of your book sitting on the table as you game with your buds.
I've used a few POD services for publishing games. I've used three, if anyone has used others, please talk about it here. I'm more and more realizing that some people find hard copy publishing very intimidating. I failed many times trying to print books, in fact I just ordered a proof from Drivethru and it came out wrong so I could see why people might be nervous about it.
Let me say that having that real book in front of you at the game table is worth the trouble.
So whats the "best" pod service out there? That really depends.
lulu.com This is the first service I used. To my knowledge it was the first platform that was all web based and it shows by their refined tools. Lulu is probably the best service for printing off a personal copy of a book that you want just for yourself. Their cover editor is the most powerful and flexible.
You can make a simple cover from just the templates they have or a full art wrap around cover if you're feeling adventurous. The other nice thing about lulu is that their bindings are high quality and they last. That wasn't always the case and I think they learned from it.
My young daughter published her book through lulu and did it mostly by herself. You do need to have either a copy of Adobe Acrobat or something that can print to Ghostscript to get a properly built PDF though. Their biggest requirement is that all fonts must be fully embedded. Really that's a low bar for these services though since they all require it.
Their biggest downside is their books can be pricey. You are paying for quality though.
Amazon Createspace I currently use this service for The Artifact. Their web tools are close to lulu's for their flexibility. Their cover creator is a little less powerful than lulu's. When submitting a file, there's a less automated approval process that takes time, so there's less instant gratification but possibly more safety measures in place. I've had fewer bad proofs from Createspace but that might just be me having some experience. They require you to buy a proof copy and then approve it when you receive it. In a way this is nice, but when you make a minor change and then have to order a whole new copy to make the change live it's a pain.
Createspace is cheaper than Lulu and Drivethru. I've also had some bindings fail with Createspace after sustained use. They seem to be getting better. The color quality for their books is also not quite as crisp, so if you have a lot of art that you're really proud of, Createspace is less attractive. All in all though, you can sell a Createspace book at a reasonable price and still make some money off the sale.
The technical requirements for Createspace is about the same as Lulu, but their cover editor requires more work if you want a wrap around cover.
Drivethru RPG I've always been terrified of trying to print with Drivethru, I'm getting ready to launch my first printed title through them (soon?). Their process for simply setting up a publisher page is byzantine and I heard their requirements for pdfs is stringent so I was always reluctant to try.
So, yes, their requirements are a real pain to try and get right. I technically haven't gotten them right yet, but they are slightly flexible on them. Their cover creation process is weird. You have to go to a website and request a template be emailed to you and you must use the template or the cover will be rejected. There are two programs they approve of you making your book in, Indesign and Scribus. If you made the book in any other program, there's no guidance on how to meet their requirements. They have a step by step walk through of how to use those two programs to produce a finished layout though. Like Createspace, Drivethru requires a proof be ordered when you upload a new file. There's also a lengthy approval process by the printer.
Because I spent a few years learning how to trick lulu into printing my books that they thought wouldn't print I may be able to cheat my way through their process. The cover I made through their approved process turned out with bad color reproduction. My interior that I made with my own process looks really good. That might be a difference in the machines that print the interiors and the covers though.
As far as quality, I've gotten one proof so far. The binding feels good, but I can't say for certain until I've used it for a few months. I ordered their premium paper and the interior color reproduction looks great and the printing is crisp. I'd assume its less crisp on their standard paper. Interior light grays are a lot lighter than expected, but that's a minor issue. My cover color reproduction is lousy. I don't know if that's because the process for generating the PDF is not quite right, but I followed their cover creation process for that as well as I could.
Drivethru has the advantage that they're a market place for RPGs and the people on the website are looking for RPGs. I may get as many downloads of The Artifact on Drivethru as I do from my own website. So if you're ultimate goal is to sell a game, Drivethru may be a good platform for you despite it's technical hurdles.
Hope this is useful to someone looking at printing, enjoy!