One should take great care when choosing a shirt for a very special, formal gatherings. Is it a wedding you are preparing yourself to attend to? Are you playing any significant role in the event? Is the dresscode set?
These and more questions should be answered before you start looking for a perfectly fitting shirt for the more posh of events.
Remember that in order to attend a black tie event you'll be in a need of a tuxedo shirt, nevermind a great looking tux and, of course, a bow tie.