I really like BusyCal! Especially the drop-down interface for the menu bar. It’s very handy to see a concise graphical representation of the month and the upcoming events and meetings.
My favorite part is the graphical design of the app. It looks really nice. I was for a time torn between BusyCal and Fantasitcal, however I am glad I decided to stay with BusyCal. I do use Fantastical on my iOS devices, however. I do like those apps. They just seem to quickly grow old since I feel like I am looking at the same thing every day whereas with BusiCal - it seems to be changing and changeable. Like life.
I also broke down and bought BusyContacts. Although I do like that app, I would never be happy until I had both apps paired together. Maybe you will like it as much as I do?