Check the recent threads. There is a long thread with many suggestions about people's favorite apps. It really depends so much on how you wil use your Ipad and what's important to you. One app that almost everyone suggests is Goodreader, a pdf reader and so so much more. There are some apps that have good reviews and advice about apps. One I like is Appadvice.
As you use your Ipad and feel the need for some app to do something you can ask here for more specialized advice. Have fun with it. i've had mine since last May and still discover new apps to enhance my uses.
If you are looking for a game that will get you going, may I suggest checking out Ultimate Hangman and Phrase Phrenzy. Phrase Phrenzy is the game we have just released and is quite unique in it's gameplay. Ultimate Hangman has a great original idea in it's drawing. I loved it the first time I saw it. I play both every day. Phrase Phrenzy challenges the mind and makes me laugh. Ultimate Hangman just makes me laugh!
The Apple App Store has a 'top ten' downloaded apps - both free and paid for - and then also listed by amount grossed - i.e. so a few downloaded but very expensive apps might list higher than a larger number of cheaper apps.
It seems to be done by country too, so you don't get confused by apps you can't download - like NetFlix.