I'm French and moved from Paris to Barcelona 3 years ago.
If you haven't decided yet, here are my 2 cents:
Paris:
* very expensive, if you don't plan on working that much, you'll end up stuck pretty much all the time because of the cost of living.
* rents are very high for small flats
* it does rain a lot, so skating from October to April can be a real struggle
* healthcare system is good, especially if you have Euro citizenship
* skate, music and art scenes are the best I've experienced in my life
* social life is great, easy to meet people and make friends through skating. Head to smaller spots like Jemmapes, Rue Léon Cladel or Palais de Tokyo if you want to meet people
* with the current situation, it will be hard to find a job and get started
* the city is full of stress, negativity and people thinking they're unique and better than everyone else
* there's literally nothing to do outside of the city, except maybe biking around. If you want to stay close to the country side, definitely not a good option.
Barcelona:
* cost of life is way better, rents are cheaper and getting down now that the tourists have fled the city.
* skate scene is a little bit harder to get into if you don't want to spend time in Parallel or Macba. FTC is a good place to start if you want to meet people, and lots of cool DIYs around and in the city
* the arts & music scene is pretty poor in my own experience. Hope you like house/electro because that's pretty much a lot of what you'll find
* weather is amazing, Catalan people can be pretty tough at first but they'll chill once they understand you're not here to get wasted and piss all over the city.
* healthcare system is really good, people speak english and are genuinely nice and caring for each others
* you can get to the mountains in 45 min, or 1h30 in the winter for skiing/snowboarding, then back to the beach in the evening for a couple drinks
I saw someone recommending northern Spain (Basque Country). I grew up in the region, Bilbao is really sick, surf scene is pretty strong too and you can get to the mountains in the winter. Food is amazing. It does rain a lot though, so you'll probably get some good weather from May to September, but the rest of the year you'll mostly be indoors.
Hope that helps, good luck with the move.