1982 LX
First one only makes my list because it was one of two my parents had:
1987 LX coupe t-top:
Saleen S351 New Edge or S197
ANY 2011-2014 Mustang with a Glass roof. GT, CS, GT500 any of them.
2011-2014 is the best body style IMO of any late model mustang.
ANY 2018+ Coyote Mustang.
Best platform for mods IMO.
I do love the GT350 and 2020 GT500 but they just can't make my list based on cost of either of them and the fact that any replacement parts are Shelby specific. It's not worth it in my humble opinion. Not for what I do with the cars anyway.