I feel this series is either head down the Transformers Animated route with most fans initial hatred being replaced by the fun it brings, or it'll be a garbage fire of trying to be hip and new and fail the franchise completely. There is probably a middle ground between but knowing the internet it'll be one way or the other.
Looking back it's not easy for me to call any of the cartoons bad so far. The 87 series was really goofy and toy shilling but was always fun, until the grimdark red skies episodes and even than I enjoyed the show for trying something new after years of the rinse, wash, and repeat of Turtles stopping Shredder and Krang from using the Technodrome.
The 2003 series seems like the closest we'll get to the classic comics in some ways and still has the best Shredder in Ch'rell. Things may have jumped the shark later on with everything past the Mystic Ninja season, but even then the tone of the series always kept about the same regardless.
The 2012 series had fun with the old while bringing in it's new touches. April got a much better role than ever before in the series, and Karai's backstory was a great touch to bring more into the series. But sometimes I think they went a bit far on their gross out moments for a kids show. And while I love the character as it played out through the series, Ice Cream Kitty? Who came up with some of these ideas But I hate to say it but it also probably had the best overall cast, but considering the multiple legacy cameos, guest stars of note and more it's hard to give the older series a hard time about it.
That gets me thinking. So far I'm not really enthused about Rise's cast. But on that note which version of each main character is your favorite.
Leo - While I do really like all of the 2012 series actors, I believe 2003's Michael Sinterniklaas had the best overall. These days Cam Clarke's Leo voice is too high pitch for me, and the rotation between Biggs to Green while not bad never seemed as good as the Leo in the 2003 series.
Raph - Sean clinches this one. Love Rob Paulsen but Raph was never really the tough guy in the old cartoon and while Greg Abbey did pretty good in the 2003 series, he always went a bit too much on the accent, which granted they live in New York, but I hate stereotypical accents. Sean Laid off it mostly and was a damn good Raph. The Tough guy that cared more than he let on.
Donny - Man it's probably a tie between Paulsen's April crushing and Sam Riegel's brain of brains. Really it's tough because Donny has always been my favorite. I like Riegel's voice much better but he rarely showed more than being the brainy one, while Paulsen's higher pitched voice grates on me a bit but got more to do than be the tech guy this time. Being both only tech guy and the high pitched voice rules out Barry immediately.
Mikey - Gotta go with Cipes. I love all three Mikeys but Cipes was the balance between the 80's and 2003 version to me and I think he pulled it off the best.
Splinter - Hoon Lee hands down. Love all three versions of cartoon Splinter but Hoon had the best story behind him and sounded the most natrual. 80's Splinter was mostly the chill mentor most of the time, and the 2003 series tried too hard making him sound old. Sadly I think Bauza maybe heading down the same way as the 2003 series.
April - While I do love Mae Whitman's April, I got to go with Veronica Taylor's 2003 April. While mostly being the Turtles Girl in the Chair most of the time, she still was a pretty strong character most of the time. That and I liked the relationship between her and Casey more here.
Casey - right off the bat 80's Casey is written off with only being a minor recurring nutball. That being said, while I do like the character in the 2003 series more, 2012's Josh Peck wasn't trying so hard to sound like a New Yorker.
And Shredder - It's tough to choose. but 2003 Shredders voice sounds so menacing I gotta go with Scott Rayow between all his Shredder appearances in the series. I like Kevin Michael Richardson and he does so well in 2012's series but between Shredders downfall in the later seasons and hearing his voice everywhere else in other series sounding so similar it sometimes blurs characters together for me. But gotta give props at least to James Avery. May not of been a great villainous Shredder but he was always a gret part of a comedy routine.