I use Logos Bible Software for my Bible study, and teaching & sermon prep. And I would definitely recommend it to anyone who is on the lookout for Bible software.
Logos has several blogs that are worth your time as well. One in particular that is very helpful, regardless of whether you use the software or not, is their Academic Blog.
Click here to see a listing of their more popular posts as they celebrate 6 months on the web.
As for free Bible software, I would highly recommend the following sites (in no particular order):
ESVBible.org is my favorite online Bible.