Look, fighting for the integrity of the word "trilogy" is like fighting for the integrity of the phrase "dick salad." "Dick salad" doesn't need me to start a war to defend the honor of "dick salad," because the meaning of "dick salad" just isn't that important to most people. My quest to apply the word "trilogy" correctly is a lonely howl into the aisles of your local Best Buy. If the word "trilogy" continues to be slapped onto the cover of any three disc set that focuses on one character, but tells a ridiculously incomplete story, my name will not go down in any history books as the one man that planted his flag when all others retreated into the hills of lazy movie marketing.
But if you go into the Captain America films or the Iron Man films, or even the latest batch of X-Men films, expecting a trilogy that you can watch in the same manner as Lord Of The Rings, you're going to be disappointed at best. At worst, you'll be monstrously confused. For instance, if you decide to start your venture into X-Men with First Class, not even an hour will go by before parts of the movie refuse to make sense. Wolverine makes a cameo wherein he tells Magneto and Professor X to "f**k off," and ha ha that's funny because he was in that other X-Men non-trilogy, where he most decidedly didn't tell Magneto and Professor X to f**k off.
20th Century Fox
Honestly, Hugh Jackman should do this in every future X-Men movie.