I like Notre Dame just fine personally, none of the other wonders from that age hold much appeal. Once all the oil upgrades kick in it saves a ton of frustration.
Plus, as a fairly large building the AI must go around, it's a decent obstacle to path the enemy into killzones or slow down tanks and cavalry. Perhaps I'll change my tune if there's a final age and I ever manage to get to it. I suppose it depends on whether wars are one's main focus or not, and whether one is trying to max their generals, airstrip, and factory troops. Two attacks or a few defenses every 48ish hours isn't worth the hundreds of thousands of oil I'd have to tediously grind and defend from IA upwards. Not at this point anyway.
Your mileage may vary.