FF XII is the better game for me:
No anime characters or romantic plot.
Great combat system
Exploration and side content
Great Medieval setting with some sci-fi.
Plot is very political and characters are good. people dont like Vaan because is not a cool anime character, he is a commoner teen in a word in war. Him and Penelo are in the story to represent the common citizen in this situation. Ashe plot is what move the story.
FF X
Stereotypical anime characters (Tidus is your extrovert care free protagonist and Yuna the Shy, serious girl..of course they fall in love)
Linear progression (But with side quests)
Excellent turn battle combat system and character progression
Plot idea is really good, narrative and characters are mediocre.
All this is my personal opinion. FF XII is one of my 3 favorites games in the series, but FFX is a solid entry anyway.
to put things in perspective, my favorites final fantasy games are: 6 - tactics - 12 - 9 and 5