The transition elements that has the lowest enthalpy of atomisation...

$Zn$ is usually not considered as a transition element as the d-orbital electrons do not take part in reactions. This is why $Zn$ exhibit only $+ 2$ oxidation state.
But since, it is placed in the d-block along with other transition metals, it is technically a d-block element and a transition metal. Zinc has the lowest enthalpy of atomization among the first row transition metals.

Elements	$V$	$Cu$	$Zn$	$Fe$
Enthalpy of atomization	$515KJ / mol$	$339KJ / mol$	$216KJ / mol$	$416KJ / mol$