Taskup is a new web-based to-do manager that offers colour-coded priority markers, to-do notifications via email and cloud sync. It's all presented in one fast and good-looking package that just might rival your current setup.
Once you sign up (via OAuth, using your preferred Google account) you can immediately begin adding to-dos you want to track. Flag them with priorities and keep them organised with drag-and-drop categories. If you set a due date for your tasks, Taskup will email you on the day. Your changes are synced as you type, and they're accessible from any other linked devices.
Taskup is in alpha, so expect a few bugs here and there. Most users can get by with the free plan, which gives you up to 1000 to-dos, but there are pro and business plans available too. If you haven't found the perfect to-do manager yet and want something simple, fast and web-based, Taskup is worth a look.