Apps are a personal choice with what it is you want. There are many threads on different apps.
Try Appshopper it's a great way to browse for apps and there is a wish list you can create so that when the app comes on sale it will notify you. A very good way to get paid apps free.
The IPad Forum is a community of members from all walks of life and from all over the world coming together to share our experiences and to help each other learn about this wonderful piece of technology the Ipad. There is a wealth of information already here in the many threads we have so doing some searches will answer most of the questions you have. If then you cannot find the answer you are seeking then by all means post your question. There are many friendly and informed members here only too willing to help you.
I agree with Leelai-apps are based on what your personal interests are. I love appshopper as well! It will give you an idea of the gazillion of apps out there for your choosing!!