I've recently been watching the original Transformers for the first time as an adult and absolutely agree. The series stays fun without being stupid or falling back on annoying and gimmicky tropes as often as it seems some other shows from the 80's did. (The same friend whose nostalgia resulted in my seeing Transformers previously tried out Thundercats and He-man, neither of which managed to hold our interest. For my part a lot of this fell on the different series' treatment of women, which Transformers all but sidesteps... but I digress.) Put another way, Transformers was so heavily and intentionally made up of blatant attempts at mass appeal it actually managed to do something interesting with them. I'll say this for a show that had to constantly introduce new models and situations in order to sell toys-- it managed to do so creatively, so that an otherwise ridiculous situation (hey, dinosaurs are cool-- let's make dinobots!) never seemed inconsistent with the tone of the show itself.
I know a big part of the show's appeal for me (and for many of the fans I've spoken with) stems from the characters of Optimus Prime and Starscream. Optimus is a shining example of leadership any human being can learn from; he's unfailingly committed to his ideals and the safety of his fellow Autobots, brave without being foolhardy, humble and honorable without becoming obnoxious, and well-spoken, primary-colors, grandfatherly-charismatically awesome. I will unabashedly endorse introducing all children to Optimus Prime so that they too can aspire to his example.
On the other hand, we have Starscream. While Starscream's voice and constant failed attempts at betrayal should by all rights make him incredibly annoying, his determination in the face of that perpetual failure in combination with the creative "cunning" Megatron so often cites make him incredibly likable. That, and the fact that his failures are as spectacular as they are hilarious, particularly when we get to see Megatron's irritated (yet consistently forgiving) reaction. I know I'm going to enjoy an episode when it revolves around Starscream's ridiculous exploits in the name of usurping leadership of the Decepticons, largely because it's going to make me laugh but also because it's inspiring in its own way.
Somehow Starscream in his bold failure is as compelling and inspiring as Optimus is in humble success. Maybe this is an artifact of having grown up alongside the Transformers generation even though I never watched the show, but as I move into adulthood I find Starscream's example very comforting. He fails constantly in the pursuit of his goals, but he never despairs or gives up, nor is he rejected for pursuing his own path. Beaten up, exiled, even destroyed-- he never loses Megatron's respect. We should all be so fortunate-- or at minimum so brave in the pursuit of our dreams.