I am not counting the cameos because they are exactly that, little winks instead of full fledged performances (though he did most of the feral work in Apocalypse since the camera didn't).
1. X2: He was just as hungry for the character as in X1, but he had refined his accent and body language, and was honestly just more ripped in terms of physique.
2. The Wolverine: Jackman got hungry again, clearly feeling like he had to make up to the fans for his previous duds and did a great job refocusing the feral, animalistic side of Wolverine with an older weariness. Felt very Clint Eastwood-like.
3. X-Men: Looked like he stepped off the page on first viewing, and he just crushed it. A few slips of accent are the main reason it's not the top spot.
4. Days of Future Past: This might actually be his best performance but it was less Wolverine-like than the above three. This is mainly because he was playing an older, wiser, and more calm Logan, which he did beautifully. But like most fans, I do like it when Wolverine gets a little less mellow and starts digging his claws into things.
I don't want to include XOW and TLS, because in addition to being bad movies, they weren't very good performances as Wolverine. That's because Jackman and the filmmakers were recalibrating the character to make him more of a romantic hero and leader (TLS) and a generic action hero out of some dippy "Commando" vein in the other (XOW).
It is also why he was so good in The Wolverine, I suspect. He became aware he had let the character get away from him in favor of movie star clichés. So, he refocused and came back with a vengeance in the last two full performances he gave as the character.
