To me, the question is not "what apps are good for the iPad2." The real question is: What do you want to do with the iPad? Then, and only then, can you decide what apps you should get.
So, what do you want to do with the iPad? Maybe we can then tell you which apps we use to accomplish that same task.
This seems to be a request that comes up often on the forum, i.e. 'what are the best..' or 'suggest some apps..' for the iPad, and I'd have to agree w/ several posters that some input from the OP as to their reasons for buying an iPad and their intended purpose(s) would greatly help members who want to respond - with 100,000s of apps available, often a cornucopia of suggestions are made which may or may not be of interest to the person starting the thread.
BUT, several suggestions that I can make are more 'reference' apps, i.e. AppStart & AppAdvice - both are available in the App store and provide much information and recommendations for some of the 'must' apps and also categories of apps w/ directed discussion -