Oh man, I ve been waiting for this.
Of special note here is the animation which I would say was the only other superhero show that could match Bruce Timm's DCAU. It is a big highlight of the show and continued the trend of diversifying animation in the 2000s.
Yeah, the high school stuff can be grating and Spike was by far the least likable character for a while (he was created because the creators refused to deage Storm), but when things hit the fan in the S2 finale it truly hits its stride. Those two episodes plus the first 6 to 7 episodes of S3 was its best run.
Wolverine was thankfully toned down, though some people would accuse him of being Worfed. But it was for the best, especially since the creators overcompensated in Wolverine in the X-Men.
I would argue that Ascension is one of the best superhero finales ever made, even comparable to Starcrossed. Funny enough, Avengers EMH tried to do the same with its finale with less success.