I’ve been a user of Logos Bible Software for a few years now. Logos 4 Mac looks like a good product. Here’s some promo text from their website:

Logos Bible Software is giving away thousands of dollars of prizes to celebrate the launch of Logos Bible Software 4 Mac on October 1. Prizes include an iMac, a MacBook Pro, an iPad, an iPod Touch, and more than 100 other prizes!

They’re also having a special limited-time sale on their Mac and PC base packages and upgrades. Check it out!