1966 D/Dart ??
My favorite would be a the '69 340 GTS (naturally) :-) followed by the '67/'68/'69 convertible 'Cuda. 273 in the '67, 340 in the '68/'69. Love the lines of the 'Cuda with the top down.
We're keeping it all LA engine here. NO Hemis or 383/440's allowed.