I've tried a few scheduling/task apps, and I'm still with Saisuke for a couple of reasons. First is that schedules are easy to copy and paste somewhere else, and second the month view and ease of changing the month that keep me with Saisuke. Saisuke doesn't have good task support though, and it looks cluttered on month view (that's a minor complaint though). I'm looking for an app that handles both schedules and tasks well.

RTM is a great app, but it lacks a month view calendar. If someone asks me if I have something happening on the 2nd Sunday of next month, I need to be able to look that up quickly. That's kind of hard to do on RTM.

The ability to duplicate a task would also be great. I have some appointments that don't take place every week.

These two features are must haves, pop-up alerts would be great if I could get it configured. I'll go with the first app that gets these two features.