Goal of the interview?

I have a question for some of those who are in banking and maybe in particular those who conduct interviews - either first round or superdays.

What are the best things to try to get across in the interview? Do I want to showcase my enthusiasm for the job? Do I want to showcase how great my work experience is, and how much responsibility I've been given by others? Do I want to show why I am better for the job than everyone else? Do I want to get across my extreme technical knowledge?

I know interviews are a lot of bragging, but should a point be made not to try to be too arrogant? There are a lot of different ways to frame your answers, and the fact that I tend to be wordy I think is hurting me a bit. I am the kind of person that can bring every answer back to why I'm the best and why I'm interested in banking and why they should pick me.

Do you get annoyed when someone does this? Should I do my best just to answer the questions fully, and try to remain a bit humble while also making sure to fully credit myself for all of my accomplishments?

Sorry if this seems a little broad or vague, but hopefully you all can understand where I'm coming from here. I have a lot of interviews coming up and I just want to make sure that I'm approaching them in the right way.

As an addendum, are there certain questions you want asked when it is our turn to ask the questions? I was criticized in my first superday for asking questions that were too "big picture" by an associate, who said that I should only be concerned about the people and the culture, and not about the firm in general and where it is going and the state of the market. Should I try to stay in culture questions to associates/analysts and with bigger picture stuff for MD's/VPs?

Thanks for any help on this issue.