Firstly, congratulations on your acceptances. All of the schools you listed are great schools. Whichever you choose, you will definitely learn a lot there.
Top 20 US schools pay great attention to LoRs so, at this point, you have to decide where you can get strong references. Barcelona GSE and TSE are great schools, however, their class size is big so it may be hard for students to shine there. But I have heard that professors at Barcelona GSE are very supportive. I have no idea about TSE, though.
In your specific case, if you believe that, you can get a 1:1 degree and good references then you should consider about going to LSE since LSE PhD is one of your aims.
CEMFI is a great school (I will most probably attend there) but if the costs of going to CEMFI are higher than going to UCL, it may be rational for you to choose UCL since you know that you can get strong LoRs there and it ranks higher.