I must admit I'm not such a big fan of any on the Transformers series, execpt this one and Beast Wars. I realyl think that the old transfromers (the ones that changed into vehicels) were rather poorly drawn, looked a bit flabby and slow and didn't have such a good character build.
This one however, corrects just those mystakes. It has super cool chacters, each with its qualities, dominant characteristic and defects, good action, better graphics and I like the animal-froms better than the vehicle forms.
Also, the plot is cooler if you ask me (no more humans to get in the way) and, not to mention the armies of vehicons, which are REALLY great made. The ending seemed a bit...too much, but overall, the best transformers series ever.