Good question. I would much rather live in the Simpson's World.
Why? Because the Simpson's are original. 'Family Guy' is good at about 50%. Sadly its other 50% is a mix of stealing from the Simpson's (not just ideas, but word for word!), time wasters, and stealing from old shows they think most forgot about.
I think The Simpsons world be a more better place to live since so many things happens in Springfield to everyone. Everyone has adventures in that town and gets into a lot of comic things. Family seems like a very dangerous place to live in since many nobody's dies every time Peter gets into a fight with that chicken. Plus many other problems they have there that wouldn't be that fun to live through, and besides the weird and fun things that only happen in the family guy world happens to the Griffin family. If you think about it everywhere else in that town is normal