http://www.e-sword.net/support.html
It is free, and you can get a lot of free versions, commentaries, etc. I find it quite useful. I also have an ancient Logos Bible Software v. 1.6 that I like.
I have both of those too. Great resources. My version of Logos was so old I still had the 3.5 inch floppies. Whose got a 3.5 inch floppy drive anymore? Just upgraded a year or two ago. Well worth it, but the look and feel is quite different and took some getting used to.