Dressing to the occasion is very important. One has to be conscious of the type of function he is going to attend while selecting the dress. Some parties prescribe dresses that have to be worn by the attendees while some have color codes which is a recent trend.
You may choose an attire that is decent and fashionable if you are to attend a casual party but need to be formally dressed if it is an official (need not be official in the strict sense) function. So, more than making a choice of your convenience and preference, you should keep in mind the type of function or party that you are to attend, the type of crowd that would form the gathering, the events that are included, the time and a lot many more while selecting your dress. The dress you choose must allow you to merge with the crowd, must be decent and, as I said in the beginning, to the occasion.
'It is the mark of an educated mind to be able to entertain a thought without accepting it'. - Aristotle.