Calling Fallout "serious" is a stretch, if you ask me. There's no doubt that the subject matter is intended for older gamers, but to be honest, I think that the appeal is more skewed toward the teen demographic.
At any rate, welcome to the forum.
I've been playing FFXII the past two days. Not really sure what to think of it yet. It's like FFXI, except not as good. The story sounds alright, but it hasn't gotten me to really care about it yet. It's not *completely* fitting the JRPG mold, but it's not completely fresh either.