Firstly I will say, this is not a personal dig at my French friends, and I have no intention of offending you. This is merely my observation and opinion. Others may have had different experiences, that resulted in different opinion.
Secondly: please don't misunderstand this sentiment. I really did love Paris. It is a wonderful, beautiful place. Had I not come straight from Barcelona, I may never have formed this opinion. However, that is how it is.
In short, Barcelona is vibrant, diverse, interesting to look at (people, buildings, views, festivals), streets are generally wide, lots of trees, good bike paths, weather is good, great location amongst the hills and beside the Mediterranean, and it is cheap to eat and drink.
Barcelona, on the other hand, is like an interesting lace patchwork. Still beautiful, awe inspiring and intricate, but more apealing because there is so much more to look at: layers, beading, diferent history in the patches, and strength being sewn together particularly well, and amongst the patches are brightly coloured be-jewelled pieces that are breathtaking.
While I found the French to be generally friendly, I felt that there was a facade that couldn't be breached unless you had a friend on the inside or you could speak fluent French. An example of this is where all the signs about the historical sites are only in French.
While in Barcelona, there is an immediate warmth from most people. They genuinely want to help, even if there is a language barrier. Occaisionally, I went shopping with a friend who speaks Spanish quite well and I felt that there was even more warmth.
They celebrate diversity and they want to share it. Most of all they invite you to join the party.
I am working in the sun, with birds singing, listening to people laughing in the street. Several hours ago there was a percussion group marching in the street. Why would you not love Barcelona?