I finally finished watch Batman: The Animated Series as well as Superman: The Animated Series.
While B:TAS is certainly the better of the two, S:TAS is certainly not without its charms. The third and final season was rather lame, though -- it felt to me that Supes became a supporting character in his own show, with too many episodes focused on other superheroes. Of course, the episodes which featured Supergirl and Darkseid helped to make up for the rest of the season (partially, anyway).
I'm currently working my way through X-Men: The Animated Series and I've begun to watch Lois and Clark: The New Adventures of Superman.
I'm currently into the third season of XM:TAS, and despite it being very "'90s X-Men" I'm certainly loving it. Lois and Clark, on the other hand ... well, let's just say when it comes to Dean Cain's performance as Clark/Superman, I feel the polar opposite I feel about Chris Reeve's performance. Whereas I feel Reeve played a great Superman but an awful Clark, I feel Cain played a great Clark but an awful Superman; when I look at him in the Superman costume, I just see Dean Cain wearing a Superman costume; he doesn't change his voice or body language between the two roles, and frankly it destroys my ability to suspend disbelief when the other characters fail to recognize that he is both Supes and Clark.