Here are my picks for the top 20 must have iPad apps. They are all free and some might have optional in app purchases. The games I chose really showcase the coolness of the iPad, great for showing off to your friends! Of course the news, radio and TV apps I chose pertain to Canadians, in particular for Calgary, so you should search for your local stations/papers in the app store.
News & Weather
National Post, The Globe and Mail and CTV News also have apps. You may also want to check out CNN, BBC News and The Huffington Post.
Radio, TV & Film
CTV, CBC and Global all have apps to watch local TV.
Games & Fun
Hobbies & Interest
Facebook and Twitter have iPad apps. LinkedIn has an iPhone app only. HootSuite accesses all of your accounts.