Lifelong fan. Transformers is a lot to get into as a busy adult. Here's my view on most of the main stuff:
G1 cartoon is goofy but establishes basic characters and plot. Movie is great.
G1 marvel comic takes itself more seriously and manages to establish a lot of deep lore used throughout the franchise. Worth a read if you really want to get into the meat of G1.
G1 anime sequels are a bore in my opinion. But do have some cool characters and concepts. There are much better robot shows from the era.
Beast Wars is great. Sequel to G1 (as an idea. References parts of the cartoon and comic) and has fantastic characters with depth. Still holds up to this day.
Beast Machines is not a bad show imo. It just happens to have some weird inconsistencies. Otherwise it's a well-written show and is interesting to see what happens after Beast Wars.
Car Robots/Robots in Disguise is an anime for kids but manages to be the closest thing to the G1 cartoon than anything else in comparison in my opinion.
Armada is bad. Energon is worse. Cybertron isn't bad but it's a braves show just not as good.
Bayformers are all trash. But they did reinvigorate the franchise and have some kickass robot designs.
Animated is alright. Good kids show that oozes G1 nostalgia.
War for cybertron, fall of cybertron, and TF Prime are all in the same continuity. In my opinion they are the best G1 reboot iterations that have adult fans in mind. Really enjoyed them all.
The current cartoon, Robots in Disguise is a sequel to Prime. While it's a pretty good cartoon for kids and makes a point to stay in continuity, it feels like much more of a toy commercial. I was looking forward to seeing starscream return, but when that story arc basically amounted to "buy all the mini cons" I wasn't feeling it.
Out of everything the only ones I feel that are worth going back to are the G1 movie, Beast Wars, and the games + Prime.