Hi Fran,
me , I pretty much loved them all. With each generation they had new & exciting features.
Going back down memory lane ( arranger keyboards only newest to oldest , (had a few arranger modules in between, the ra series , korg i5m & quite a few synthesizers & samplers, but I won't bother with those) .
Kn7000
9000pro
va7
kn5000
g800
korgi2
Kn3000
E86
kn2000
kn800

best wishes
Rikki