People brought up OmniFocus a number times over the course of my informal survey. Donald McMichael told me "Omnifocus is powerful and highly configurable from a process standpoint, and thus has a somewhat steep learning curve. The good news is that there's a fair amount of instructional and user-generated setup documentation/videos."
Omnifocus will sync all of your tasks across different devices, but you'll have to pay to install them on each one. Omnifocus for Mac costs $80, while the iPad and iPhone versions cost $40 and $20, respectively.
Jeffrey Huckaby, CEO at the server-management firm rackAID, says, "Some of our team use Tracks, a free, open source solution" for project management. Tracks was built using the Web-development framework Ruby on Rails, but you needn't be a Ruby programmer to harness the power of this software. People who don't know Ruby or MySQL from a hole in the ground can download Bitnami Tracks, which lets you install Tracks as a traditional Windows program without worrying about all the backend server stuff. Once installed, Tracks is an easy-to-use, browser-based GTD application with a minimalist interface. I've been using it myself since researching it for this post, and it's a keeper for me.
MindManager is a suite of tools for managing projects and teams, and for mapping out complex ideas and designs. Sherrie Gossett, Digital Channel Management at The Atlas Society think tank, suggests Gyronix Plugins for MindManager as GTD apps. Specifically, she recommends Gyronix ResultsManager and GyroQ.
"Using both of these plug-ins, I can quickly sketch out projects with due dates and resources assigned in Mindjet's MindManager. Each day, at the touch of a button, I can generate a graphic dashboard, which shows me exactly what my next actions and steps are on each project, what deadlines are pending or missed, and what I owe anyone (e.g. document, phone call, sign-off), and what anyone owes me."
Powerful stuff, but it comes at a cost: MindManager for Individuals starts at $20 per month, and the Gyronix plug-ins range in cost from $30 to $300 depending on what you're looking for.
Combinations of Various Tools