I have the first complete set that Rhino put out about 8-10 nyears ago. In seasons.  I watched them once.  The first season was awesome,  it gets kind of stale in seasons 2 and 3, but then for some reason in season 4 it gets awesome again an just stops?????  with the headmaster storyline.  Wish it would have kept going to be honest with you.

I have the Beast Wars set, an to be honest if you watch it from the beginning to the end, it really is very good.

I also have been reading the Transformers novel that just came out...The official history of the war fopr Cybertron..Really is very good.  I read while I am on the cross trainer.  I only read about 30 - 40 pages at a time,   helps the time go by faster to be honest with you.    But the book is very good!.  I reccomen it if you can pick it up.  You get a sense of why Megatron keeps calling Optimus Brother all the time.

Season 1 was the strongest, but I still liked Season 2.  those are the episodes the 7 year old in me remembers most. 

Beast Wars was really good.  and I like how they tied it in with the original

I think the Original series sort of lost it's way sort of when the movie came out.  I remember seeing an episode when I was rewatching it where the Autobots were driving through a town and on the banner of a movie theater it actually had an advertisement for the transformers movie.  This is where it became all about the selling of the toys to me.  I am probably wrong as it always was about the selling of the toys.  But it really got bad here.  I also was sort of sick of Optimus, and wanted Rodimus to succeed, but he was such a horrible leader.  you just knew they were bringing Optimus back at some point.