ivalice is merely okay.

[Wolf Kanno]

I've only gotten half way through Vagrant story, and a million times through FFT and I have barely seen any connection.
I haven't played FFTA or TA2, but I haven't seen and connection from FFXII to Vagrant Story or FFT.

Don't chose randomly, FFT is miles ahead of FFTA

Well... VS takes place in the Kingdom of Valendia which is the region where the Archadian Empire is located in FFXII, there are several references to both Delita and Agrias as well. The Delita one being very interesting as its a reference to where he is buried in Ivalice.

That's to name a few. Its where TA fits in is the tricky part.