MOO3 was the first game in the series that I played. However unlike most fans at the time of its release I did not experience disgust or disappointment, but rather enjoyment. It felt like a rich experience with plentiful of options and a nice, somewhat dark, empty-space atmosphere. I was young at the time, so it took short while to get the hang of the UI, but when I did it was like opening an ancient treasure chest, with more interesting systems and mechanics becoming available as I understood them.
Eventually I got to play its much more beloved predecessor Master of Orion 2. While I did enjoy it as well, it did not feel as rich and rewarding as its follow-up, but more shallow, but also to its credit, more accessible.
I fired up MOO3 a few days ago, and found as always when I have returned to it, that I enjoyed it very much. In my book it is the best in the series, though I can understand that other people would not agree with me. The atmosphere is very different, and so is the game play. If I had played Master of Orion 1 or 2 first, I probably would have disliked it. But on its own legs it is very good.