FIU is objectively better than Nova (tier 3 vs 4 respectively). Right now stetson is the best choice but FIU has a good future.
You see there's the problem with using a subjective ranking like USNWR. (and it is subjective) Nova has a much larger alumni base. Much larger. Nova grads are in almost every major firm in South Florida. If one was to just look at the rankings, and not do any other research, than yes, FIU would seem the better option. But its really not for job prospects. Too new of a school. Bottom line. No alumni base, and therefore employers don't really know the quality of the students coming out of FIU. 10 years from now will it be ahead of Nova? Possibly. But for now, even though USNWR ranks it nominally higher, its actually not better for job prospects.
Is FIU cheaper than Nova? Absolutely. And that's a big factor to consider when you are looking at a school. It would be hard to justify the extra 20 grand for Florida residents. (see I'm defending FIU now) But if you're an out of state student, or if you have a scholarship to Nova, then you may wish to go to Nova simply because it will give you the better oportunity for jobs. (even if you wish to work in the public sector...where alumni connections are much more important)
Stetson is still better than both. (Oldest Law school in Florida, hence many more Alumni who can make hiring decisions) And will likely be the better school for the immediate future. I can't stress enough how important it is to have a large alumni base to work with. Alumni are loyal to their own, and if the alumni can make hiring decisions, they will take you over someone who went to another school with roughly the same credentials. Now if you graduate in the top 10% of your class, you will still be able to get a good job no matter who the hiring partner is or who's on the hiring committee. But its a lot easier for the people outside of the top 10% to get a job if you've got a connection to the people who make decisions. (i.e. Alumni)
Ok...I think I've said enough. Bottom line: Stetson, Nova then FIU for whats best to get a job. Go to Stetson then Nova if you can handle the price over FIU. If you can't then go to FIU. This can be revisited in 10 years, but for now this is the best choice.