4. Justice League
When the Justice League animated series was commissioned in the early 2000s, the decision was made to keep it set in the DC Animated Universe. Thus, the Batman that we saw in both versions of the original animated series and its sequel Batman Beyond would return for the middle chapter of that story as DC's iconic Justice League united.
Of course, the legendary Kevin Conroy returned to voice the Caped Crusader again and the character design was mostly kept the same. Batman was wearing a version of the Batsuit that he donned in the The New Batman Adventures, which sported the all-grey bodysuit, the utility belt with more realistic, square-shaped compartments, and the standalone bat symbol without its yellow backdrop.
There were some minor changes, though. The animation style no longer needed to be as sharp or dull (from a color standpoint) as the '90s animated revamp, so while it was essentially the same Batsuit, it didn't look exactly the same. For starters, Justice League used a more colorful palette, so the cowl, gloves and boots were glossier, adopting a blue sheen more akin to the original Batsuit in Batman: The Animated Series. The design was less sharp, too, with more definition in Batman's physique and longer, more rounded bat ears to complete the look.
Like most DCAU upgrades, it was a more modern version of a classic that still maintained all of the original's identity.