Many of my fondest memories in gaming came from FFXI. Seeing a thunderstorm in Qufim for the first time, or riding on my first Airship to Kazham with a couple of other people who had also never been. Seeing the level 25 mission dragon and thinking to myself "Oh my god, we are so dead." I even logged my character off at that peninsula overlooking the ruins of Tavnazia because I wanted to quit FFXI at a location that reminded me why I played FFXI in the first place.
The first time I entered Qufim I thought to myself "wow, this place is rather impressive. Why are people talking about seeking shelter at night? It can't be all that bad!" I would have never thought that Qufim would be a focal point for so many story elements and much of the game for, well, ever. It started off as an interesting place and got more and more fascinating once you learned that every element of the zone was important.
The first time I entered Coerthas I thought to myself "wow, this place is all messed up. I bet there's a ton of interesting things happening here and things that have happened in the past that I'll get to see!" Well, guess who was wrong!
FFXIV started off strong, but the story elements really weakened for a long time. I never felt like anything I did during any of the mission quests after the first one were of importance or significance (until the rank 46 one, that one was just awesome.) There just isn't that sense of awe seeing things anymore. Sure there's a few nifty things here and there, like the purple smokestacks in Thanalan, the Bahamut skeleton in Mor Dhona, and the huge city of Ishgard, but none of those things have anything to do with the game right now. They're just pointless decorations, no more of a boon to the game than the pretty flowers growing off the side of the road.
I thought that the reason I couldn't get that feeling anymore was that I was getting more difficult to impress. Maybe. But there's definitely times when I still feel genuinely in awe of the situation, or when I feel that I've overcome something great... they're just too far and few between, and I have yet to really feel that more than maybe twice in FFXIV.