Omnifocus is very good, but for me i found it a little ott for what i need
I now use Todo, which is perfect for me
I sync it to iCal via a published calendar from Toodledo.com, this makes it a read only calendar, I was thinking of setting up direct sync to ical but didnt because of repeat tasks, so i just use iCal to view and then goto the web/iPhone to make changes
From what I have read, if you have repeating tasks in ToDo, these will be fine when synced with iCal aslong as you dont mark them as read in iCal, if you do the task will end as iCal cant handle repeats