The strongest candidate will be Real Madrid. They are leading with 1 point if Girona got a draw result against Real Sociedad. They got difficulty to attack because Girona played without their main striker. I don't know what's happening with Artem Dovbyk, but he is the machine goal of Girona. However, Real Madrid will also be difficult to get 3 points in the current matchday because they will play against Atletico Madrid. Atletico Madrid is often to be an obstacle for Real Madrid to collect full points. However, I believe Real Madrid will win the upcoming match because it will be at Santiago Bernabeu (Real Madrid home).
I still believe strongly like you have speculated that Real Madrid has got the best chance for the la Liga title this season, although Girona has been really relentless in the struggle to staying at the top of the table and it has made the race quiet interesting as both teams keep alternating position by each passing week but in the end leats see who gets it.
Girona has really shown doggedness and consistency to see if they can be the winners of the la Liga this season but then they still don't looks to me like they will win the la Liga this season, Madrid has got two races they are in currently, one is for the la Liga and this other is for the champions league and it's looking most likely that they may succeed in get the two by the end of the season because they have got only one strong rivals each in both leagues, Manchester city happens to be the strongest rival in the champions league while Girona in the la Liga but I don't see Giron aas much of a problem to Real Madrid yet.