Honestly, I don't think either of them transcended the comic book genre
For all the praise heaped on it, there's nothing special about the story of Black Panther - and the idea that the most Technologically advanced nation in the world decides its leadership based on Ritual combat is dumb.
I feel like Chadwick Baseman got the short straw I that one. After an amazing performance in Civil War, probably the standout in the film ( and definitely the best character arc) - he felt like a supporting character in his own film, and thr final fight was let down by mediocre cgi.
However, you have to admire his determination and grit, as he would have been very unwell during filming. I have no doubt he would have gone on to much greater things - probably would have become the next Denzel Washington.
Also, Andy Serkis was wildly entertaining- wish they hadn't killed him off.
As for the Batman, on a rewatch the film's flaws start to become more apparent. Some people love it, to me it's probably the 4th or 5th best Batman film. ( TDK, 89, BR, BB, TB, LB, TDKR, BF, BvS, B&R )
So, I'll go with Black Panther. Definitely left more of an impact on me than the Batman - and I'm a huge Batman fan.