Batman: TAS is my favorite of the DC cartoons, and probably the best superhero cartoon ever. That said, its art style when it switched to a more Superman: TAS style was a big downgrade in quality. The style worked for Superman, but made everything look way too cheerful in batman, and made it more unrealistic. The show was still good, and the style went on to fit well with Justice League/JLU, but it just didn't work well with Batman TAS. The Joker was pretty much ruined. I LOVE Hamil's Joker but its painful for me to see him in the Superman TAS style, I'm glad he went back to normal in BB and JL/JLU, even if Batman stayed Superman TAS style.
Besides Batman TAS, I love JL/JLU, really like Superman TAS, liked Static Shock, thought Beyond was very hit or miss (Return of the Joker was excellent, though) and never watched the Zeta Project. I liked Mask of the Phantasm, Return of the Joker and Sub-Zero, but I thought Mystery of the Batwoman was pretty bland.