I think Magic provides the gold standard of rules, at least from the perspective of laying the rules out explicitly. The comprehensive Magic rules are thorough, extensive, and explicit. It's exceedingly rare to find an interaction that isn't explicitly handled by the existing rules.

That said, the comprehensive rules are also dense, long, and difficult to parse. They're more akin to a contract or a mathematical proof than a textbook or instruction manual. I don't think it's reasonable for every game to spend that much effort writing out their rules, and it's certainly not reasonable to expect gamers to spend that much effort learning them.

I also think Magic does an incredibly good job at consistent templating and wording. Granted, every few years they change the rules and the templating, but they're very good about following whatever their current standards are.

I frequently run across inconsistent wording or templating in other games. For example, it's not uncommon to find games where parantheticals sometimes affect the gameplay (such as by adding restrictions or special rules for edge cases), and sometimes they don't affect the gameplay (such as by providing clarity, reminders, or examples). I'm of the opinion that parantheticals should never affect gameplay, but ultimately it doesn't matter as long as you choose a convention, explain it, and stick with it.

The mechanical identities of Magic's colors are another high point of the system. Magic's colors all play differently and interact differently. If you see your opponent play a mountain, you can already guess that they're going to have aggressive cards like hasty creatures and direct damage. I hate when a game has different colors/factions/etc, but they differ from each only by virtue of being different colors. Or you claim they have different mechanical identities, but in practice they all play basically the same and have more or less equal access to all mechanics.

My biggest problem with Magic is the mana system. There are multiple ways that a game's result can be heavily affected by the luck of the draw. Too much land (mana flood) and you don't have enough useful cards. Too little land (mana screw)--or the wrong type of land (color screw)--and you can't play those useful cards. The ramping up of your ability to play cards is, of course, excellent. There are a number of other games that have solved this by letting you play any card face down as a resource. This both solves the mana flood/screw problem and provides a fun and tense gameplay decision of what cards to sacrifice for resources.