title: Dictionary, List or Array?
body: <p>I'm writing a service where performance is essential, and I'm not sure what is the fastest thing. I have a few Objects (50-200) which each have an ID in them (ints, e.g. 84397 or 23845). Would it be faster to have a Dictionary, a List of KeyValue Pairs or a List with the indexes set to the IDs with the rest having null values or an array with the same idea?</p>