Fastest reaction time in the Arrowverse?

Savage has the best feats out of the three.

Obviously Savage

Savage

Crossover Savage was the best but after he got on the LoT he got less impressive.

1. Not bullet timing
2. Actually good
3. Would be the great if he caught it on his own merits but he'd raised his hand by the time the lad fired and given he slowed it to a stop we can't know if he reacted to it full speed or had already started.

So Vandal pretty definitively, although using the feat of him deflecting bullets is a better example.

Savage and Darhk are bullet timers. Savage is a better bullet timer.

Darhk has a more impressive feat where he reacts to and contains an explosion, so he's probably fastest. Then Vandal, who's a very casual bullet-timer in multiple scenes. Then Oliver, as he's the only one of them without mystical abilities.