Granted, in the original cartoon he was a bit boring.
He just chilled on Cybertron, and only showed up when there were
In the comics, though, he'd implicitly been given the same post by Megatron, but... well, he apparently didn't care what Megatron told him, because he followed Megatron to Earth and was trapped under a landslide in the Savage Land (yes, the Marvel one) for a few million years, until he woke up recently and decided to beat the living daylights out of everybody. First, he took out the Autobots, who had just barely managed to defeat the Decepticons, and then when the freshly repaired Megatron attacked him for being treacherous (punching him out of a mountain and into a town that was miles away, with one hit, while still not entirely repaired), but Shockwave recovered from that hit with no apparent injury and beat him by splashing water on him. (The common theory is that Megatron still had unsealed circuitry from being in repairs, since splashing water on a Transformer to stop it is
That was the thing about comic Shockwave-he was brilliant, clever, and logical. He out-thought all the other characters all the time. He also invented the first combiners depicted in the story (the Constructicons) and decapitated Optimus Prime in order to use his Creation Matrix to manufacture new Transformers, convinced Megatron it was a good idea to kill himself, outfought enemies significantly more powerful than himself (and it should be noted he was able to trash the Dinobots by himself, and they were supposed to be really tough themselves), and was just generally pretty awesome.
Of course, the writer remarked that he was essentially a Decepticon expy of Spock, so it's little wonder...
Later versions of Shockwave are also pretty cool. (It should be noted that there was a long gap in Shockwave content, as Hasbro lost the trademark for the name for a while; a few semi-related characters, such as Tidal Wave and Shockblast, tried to fill in the gap, but were not as awesome. Tidal Wave, at least, did get to be awesome; just not as awesome. And I kind of like the idea of Shockblast, even if he wasn't very interesting as he appeared.) A later comic version of Shockwave had his logic-fu-based plotting powers extended to the point where he was responsible for virtually the entire plot of that particular series. One version was able to disguise himself as an Autobot and worked his way into the Autobot ranks, rising to one of the highest and most trusted intelligence positions on the Autobots' own side. And then there's this guy:
What's awesome about this Shockwave?
You know how trailers for the latest Transformers film show this big, wormlike thing that tears through skyscrapers and whatnot? (Or, if you've seen it, you know how there's this big, wormlike thing in the movie?)
(A good look at the wormlike thing starts at 2:09.)
It's this guy's pet.
In fact, there's only ever been one character named Megatron who could match any Shockwave's awesome levels or exceed them: Beast Wars Megatron.
Note that the reason he's awesome is because he's essentially Megatron and Shockwave at the same time.
He's even purple.