I have to say I think it'd be hard to fit a credit-card between what you're saying re: Lawful,
@lowkey13 and what
@Celebrim is saying. Yeah there's a minor difference but it is very much the same overall message - that the Lawful character thinks "rules are there for a reason", which doesn't necessarily equate to mindlessly following them in all situations, but does mean they strongly lean towards following them unless there is a strong G/E or personal reason not to.
However I think this is a bit off:
Never. But in terms of RPing, chaotic characters are boring. It's all, IMA DO GOOD (CG), or IMA DO EVIL (CE), or IMA DO WHATEVERS (CN).
Actually, I'd suggest all three are "I'ma do whatevers", it's just that Mr CG isn't willing to do things that harm others (unless those others are harming people), Mr CN probably has some kind of moral compass or moral code, even if it's not very consistent, and probably isn't just "down with murder" or the like unless there's a "good reason" (whatever that might be to him), whereas Mr CE may well present identically to Mr CG 90% of the time, but when it would benefit him to murder an innocent or set a boat full of nuns on fire or whatever, he'll just go right ahead and do it. Just because you're CE, for example, doesn't mean you go around looking to do evil (unless you're a supernatural exemplar of some kind). It just means that when it seems like a good idea to you to do something horrible, nothing is stopping you, I would suggest. CG is particularly unlikely to be going around looking to do good - many CG characters are the type of people who actively hide in the woods or the like. It's just that when they find a weeping halfling-child wandering in the woods, they'll probably at least take them back to society and not rob them, whereas the CE character may well ignore them, or rob them, or even take them back to society (if that has the most benefit to them - which could be financial, or in terms of self-image, or whatever).
As such, Chaotic characters are not always as boring to play as you suggest. Lawful characters have interesting conflicts, but they also (particularly LG characters) can end up being rather predictable, especially if the DM isn't putting challenging situations in their way, and can end up being sticks-in-the-mud, even in a good group when played well. I would go out and say CG is actually the most boring of the Chaotic alignments, in practice. CE at least keeps people on their toes!
Watching the Expanse at the moment and it's characters are fairly trope-y and straightforward but at the same time do work fairly well for D&D alignments. For example, Miller is basically CG, perhaps arguably CN, which is why he isn't a very good police officer, but he takes moral/ethical decisions which are quite sound morally/ethically (esp. from a utilitarian perspective bizarrely enough)/rational, just y'know totally illegal and unlawful, and he doesn't bother to check with anyone or listen to any advice or what the rules are supposed to be. Amos, on the other hand, is a good example of a very playable and kind of interesting CN, or even CE. He's almost completely amoral, but because he has just one rule - "What would Naomi think?" (or however you want to put it), he's actually very reasonable.
I think there's always the danger in alignment-related discussions of think people always pursue their alignments, are defined by them, but I suspect with mortals (or really anything but supernatural exemplars) that's very rarely true. People are driven by their motivations and personality, and their alignment should reflect that. Reflect what they value, what they're willing to do, what they're not willing to do. CN doesn't have to be "Captain Random McLulz". CN can be a largely amoral person who places no value on the rules of society, but is smart enough to follow them, and may have personal attachments or values that make him actually very reasonable. Honestly Amos is arguably more reasonable and interesting than Holden (who is in some sort of LG-NG zone depending on how he's being written this episode - even his initial action which starts the whole thing is both L and G strongly). Maybe you can blame this on bad writing or the Holden character being fundamentally dull, but his dilemmas are frequently the least engaging ones on the show.
So a Chaotic person who is RP'd properly may well be as or more interesting than a Lawful person, I would suggest. Bad RP, treating people just as alignments, not people, is where Chaotic starts to break down in terms of being interesting.
It means that many people who choose to play CG, CN, or CE (aka, one of the Chaotic alignments in the nine-point system) choose that because they believe that chaotic = freedom = no constraints on their choices.
Hence, CN = IMA DO WHATEVS, MAN, U CAN'T STOP ME!
This definitely happens, but it's bad RP that's the problem. A badly RP'd Chaotic character is likely to be more boring than a badly RP'd Lawful character. He's also less likely to cause the game to lurch to a sickening halt over some minor point of lawfulness, though. In both cases bad RP causes things to suck.
With good RP, where the personality comes first and the alignment emerges from that (or they're created in accord with each other), Chaotic can be very interesting.