Which is better for self publishers: Lulu or Lightning Source?

Lightning Source is not really interested in anyone but very professional publishing companies. Really. Read their website. If you can figure out what they are saying, you're much smarter that I am, and I've been running a small press for 10 years. I use Lulu,and recommend it to others. The thing to remember is, doNOT buy their "packages," no matter how wonderful they say it is going to be for your book. It is not. Just go in there, feed your text through their system, use one of their free covers or get your own, and your book will cost you significantly less than about $10 per copy. Good luck!