Thought I'd contribute my 2 cents to this thread...
Since I'm cheap and try to do my research my vote is for www.IRBrand.com, very similar to ViralPDF (and I believe the same price. To me it seemed easier to use, a bit more updated and worth the money. I was unable to find anything for free that even remotely came close to the power and ease of use.
In addition you may want to look at "Office Ready Pro" it is a plug-in for MS Word that has nice templates that really dress up an eBook.