But when I switched to the iPhone over the summer, I needed a new set of tools.  In my typical optimizer (read The Paradox of Choice) fashion, I went crazy with research trying to find the perfect application for my imagined needs.  None were perfect, but I settled on OmniFocus, which required a somewhat-tricky iMac-iPhone configuration to get the wireless sync to function.  OmniFocus had a great user interface, and it worked.  I paid the hefty $80 fee for the Mac application and the $20 fee for the iPhone application and the $99 MobileMe subscription fee that enabled sync — and I was mostly happy.  The only problem was:  I didn’t use it.  It lacked a PC or Web-based client, and it was too inconvenient to rely only on the small screen of my iPhone for my to-do list while at work.

So when Remember the Milk released its new iPhone application on the Apple Store (it already had a Web-based version optimized for the iPhone), I decided to reconsider.

Here are the features and functions I now realize I must have:

• GTD-system “projects” and “contexts” support
• Offline iPhone client (for airplanes and other places without Web access)
• Web-based application –> I realized I need a Web-based application more than a desktop client, because there are few circumstances in which I’d be using my PC at work or my Mac at home without Web access, and I could use my iPhone in those situations!
• Wireless syncing across devices and platforms
• iPhone-editable projects, contexts and text entries

Compare, contrast . . . Remember the Milk is the clear winner.  Lamenting my sunk cost in OmniFocus, I’ve ponied up the $25 for Remember the Milk Pro (which enables iPhone-Web sync) and switched, based on this absurd analysis (click to enlarge):

Yes, I’m a complete loon.

In sum:

• EasyTask Manager met most of my functional needs but was simply too hard to use, both the iPhone and the Web-based applications
• Evernote I consider more of a repository for storing information and isn’t suited for the GTD system and far too slow for an everyday to-do list
• Nozbe lacks an offline iPhone client – a deal-breaker for me
• OmniFocus is expensive and lacks a Web-based client
• Things looks great but didn’t have sync functionality when I last checked and has only a Mac client, no Web access

That left Remember the Milk, the award winning Web-based application now with an iPhone application, as the clear winner.  Most importantly, it works for me:  I’ve been using it daily.