It's common knowledge that productivity means getting shit done, not fine-tuning your task management tools. Improving the usage experience from time to time may be necessary, though.

I've been using OmniFocus for managing my tasks for years. In the company, we're now using Asana with great success, but for my personal stuff, I've kept using OmniFocus so far.

I've got a bunch of customised perspectives that show me certain aspects of my workload. The most important ones sit in the tool bar and I'm happy to have happened upon a collection of icon sets that give the OmniFocus tool bar a consistent design. You can find them over at SimplicityBliss.