I discard Italian and Portuguese as options. When I read texts in either of these two languages I am able to understand the vast majority of things. Portuguese is definitely the one that resembles the most to Spanish. What's more, the good thing about Portuguese and Spanish is that you don't need to learn the other language, most things will be understood. Italian is also very similar, but it's much easier if you know Valencian, which I also speak.
Now, between Romanian and French... Written, both seem equally difficult, and I would French is even more difficult. I know very, very, very basic things in French, but only written and I wouldn't be able to have a basic conversation at all. Pronunciation in French doesn't help either, it's quite difficult for us, as what is written is pronounced exactly the same.







