Which of the cartoons are you referring to? As I see it, most of the animated endeavors after G1 had varying degrees of success.
Beast Wars: Surprisingly excellent, especially for it's entry as a mid-nineties production. Not only did it preserve a great deal of history from G1, but it crafted a fairly unique time-travel story of it's own. Plus on re-watch the animation and voice acting still holds up incredibly well to this day.
Beast Machines: Interesting overall plot concerning balance between technology and nature in society. Suffered from extremely poor pacing, writing staff missing their target demographic by a mile, characters personalities changing in ways that made no sense (see Rattrap) plus transformations that were ehhh, you'll see:
Also, the overuse of Cell-Shaded CGI (personal complaint).
Robots in Disguise [A.K.A] Car Robots]: Doesn't count. Re-purposed anime series having nothing to do with actual Transformers.
The Unicorn Trilogy [Armada, Energon and Cybertron]: I could just say "Pokeformers" and I know the argument could be over, but that is far too simplistic. The basis of Armada was interesting, but quickly devolved due to never-ending filler episodes and hilariously bad dubbing on the part of the American importers. Energon and Cybertron did nothing to help either (given the additions of very stiff Cell-Shaded CGI used against traditional cell animation). Ultimately considered a success with its target demographic of boys between 4-9.
Transformers Animated: While not giving the story away, this series is by far the best Transformers story since Beast Wars. Besides having an awesome alternate history storyline, it has several other things going for it as well: Top-notch voice acting, a continuing serialized plot, engaging action sequences, characters that actually feel Three-Dimensional (even though they are technically drawn Two-Dimensionally) and finally HUMOR. This is something that the last four series seems to have forgotten. To make it better, it's also humor that adults can appreciate while mostly flying over their kids heads. Point in case:
The only thing I can say would possibly put people off may be the animation. But if you are like me, I became okay with it after several episodes. So if you can get past the look and general style of the show, you are in for a real narrative treat.
