Ranked in these QuestionsQuestion Ranking
Pro Supports multiple calendar platforms
If you're locked into using an Exchange account, Google Calendar won't work without 3rd party syncing options. Fantastical works flawlessly with Exchange and with Google Accounts so you can have both. It also supports iCloud, Office365, Yahoo, and Facebook calendars.
Pro Beautiful and highly polished design
Pro Fantastical can comprehend natural language
You can copy and paste a line from a meeting note and Fantastical can copy down and present the relevant information
Con Only supports iOS and OSX
Fantastical doesn't support web, Windows or Android.
Con Expensive for a single utility app
Fantastical on OS X costs $49.99 and an additional $4.99 if you want to use it on iOS.