Well it seems a weird question, but I'm going to play one of those games, which one has a better story, I really want a mature and deep story and I think both of them have that, the gameplay is important too don't get me wrong but if the story is good I can let pass a few flaws on the gameplay.

Which one will you guys recommend me to start playing?

BTW I already got Xenoblade (a friend can lend me his wii and the game to play it) Fable on the other hand I will buy it (or not, depends on what you guys tell me) from steam now that it is 75% off. (I want it to buy heretic kingdom but gog never put it on sale -.- so it's a shame)
Thanks a lot.

Fable 1 is a great game but I wouldn't say the story is mature in the slightest. I'd say Xenoblade is better (though they are really hard to compare because they are completely different types of games). Fable 1 is still worth playing and if you have to pick one to play first I'd definitely go with Fable because it's way shorter.

The length of the game is not a problem, in fact I like long games(100hours type of games like FF for example).

Wow, Fable for PC? I never played it, I never had Xbox, and assumed it was Xbox only. It always seemed interesting. If there is a DRM-free version I will check it out.

As for Xenoblade, it is both flawed and amazing at the same time. It is very unusual for a traditional JRPG. It has NPC/monster schedules (based on day/night/weather), the ability to shape relationships between NPC, a reputation system, features that is more typical of CRPGs.

But in typical JRPG style it is bit heavyhanded and explicit in its telling of the main story, the cutscenes, which get in the way of the open-world exploration aspect of game. I think for this type of game it would better to leave a bit more to the imagination and let the player fill the blanks a little. If you do explore and do all the side quests it might take up to 200 hours. The sheer scale and detail of the game world is just amazing, so I think it is worth the time. I actually play with Classic Controller/Pro just for easier camera control to view the beautiful landscapes.

Despite my objections to the cutscenes, the story is very interesting, and the landscapes will actually constantly remindsyou of that. If a crazy, ridiculous storyline is important to you, then Xenoblade is definitely a game worth playing.

Thanks for your answers I'm gonna give a try to xenoblade after all