Have you seen the Eiffel Tower for real ? Sorry to ask that question but the thing is simply that it's very hard to get a real impression of how huge it is only in viewing pictures of it.
I live in Paris and each time I get at the basis of that structure, it still amazes me about how huge it is. Generally speaking, I would say that actually, not only it's height, but also its width, makes the building impressive. The four feet of the tower forms a square of 125m x 125m. The first floor is at 60 meters of height meaning about the height of a 20-story residential building. It gives a feeling once you're at the bottom of it of pure hugeness... and all this has been built during the 19th century.
Notre-Dame is indeed impressive but there are many other impressive cathedrals. Amiens is indeed the largest gothic cathedral in France, and I've personally enjoyed the Kölner Dom even more. Afterwards, you have off course Saint-Peters basilica even if I agree it's not really the same kind. As for Versailles, it's true that everything is out of scale : the different buildings, the furniture, the massive garden perspective reaching the horizon. But still, I would say that Eiffel Tower remains the most impressive, at least to my own eyes of local.
