There are pros and cons to both.
1996 is more of a unicorn, one year only things that can get hard to find. BUT 93-95 and 97-98 full range of cars are also unicorns.
1996 pro is OBD-II, for me that means simpler emissions testings (plug into port, if it passes I can get 2 year registration).
Really the only visual difference between 95 and 96 is that in 96 they added an armrest in the middle of the back seat.
When I first went looking for a Mark VIII I thought I had to have a 96. But the more I looked at them and found the one year only things for 96, I ended up getting a Mercury Cougar instead. Then when I was looking again, I liked the Gen II better even if they don't perform quite as well as the Gen I.