Funded PhD at low ranked school(s) vs one year funded TA at a top 5 school
There are so many confounding factors in these sorts of decisions, that it really has to come down to you to decide.

That said, my opinion is you always go with the funding.

Not only for the obvious benefits of having money.  The main benefit as I see it is the school's signal of interest in you, and desire to have you in their program.  Irrespective of what you think is the best fit, these schools see a lot of students, and also have their own opinion on what students are good for their program.  Your two offers with full funding looked at you and said "we want this person," and then put money on the table.

By that metric, the first school has a much more luke warm response.  Presumably they fully funded some other students, but decided against extending full funding to you.  The "why" of it is immaterial at this point.

That leaves just your 2nd and 3rd options.  It sounds like number 3 is an excellent fit that you're excited about, from what you've written.  Regardless of what you pick, congratulations on having multiple offers to pick from though!  This is a good problem to be struggling with.