i've played all of these games, i still have the carts for ff4, ff6, and chrono trigger (secret of mana too 😀)
ff5 didnt really pull me in....people tell me it gets better later on, but man i just got sick of playing it. (ifrit's hard as f*#$ing hell too)
ff6 is great, i've probably played that more than any other game in my life, and i've been playing it since around when it came out (i was like...10 or 11)
dw7, i rented and didnt play much, but people say that the story is reeeeeally good, and that its really fun. also the game is supposed to be over 100 hours, which is insane.
i couldnt really recommend one over the other, it just depends on whether you'd rather play a (or 2) classic game(s), or whether you'd rather play a new game.
i own anthologies, and hopefully i'll get dw7 someday (i'm broke as hell so it wont be soon 🙁)
either way you cant go wrong IMO 🙂