The first one was also good because the robots were minimal, and even though the deceps had no personality, they still felt individual like each one mattered. There was a clear strength and power difference there, so ignoring that the humans helped take them down (one a little too easy), it took teamwork from the smaller, weaker Autobots. Prime was a good enough warrior and big enough to take any them on (won his first fight with ease), but was still a little outmatched by Megs... as he should be on a pure power basis (at least if you throw in his biggest weakness, his compassion for humans and innocents and trying to protect them from being hurt in the action).
If they had put a bit more direction into the robot scenes (completed the motorway fight like the novel, and cleared up Barricade's fate), and tightened the editing.. and given a bit more development to at least the Starscream and Megatron dynamic (they at least improved that in the two sequels), then it could have been quite good.
But then everything went more downhill with an already with the sequel. The only good parts OP'd Prime that much that Megatron and then The Fallen looked like punks.. All the potential of the Constructicons (apart from the Bumblebee fight) wasted. Decepticons reduced to unidentifiable clones to give Ironhide and friends something to shoot at.