Formal:
* Eristic: This is the most precise term, referring to argumentation for the sake of victory, often without regard for truth or logic.
* Polemical: This implies a strong, often aggressive and contentious argument.
* Contentious: This emphasizes a tendency to argue or disagree, often unnecessarily.
Informal:
* Quibbling: This suggests arguing about minor details or unimportant points.
* Nitpicking: Similar to quibbling, but focusing on finding faults or flaws in an argument.
* Hairsplitting: This refers to making very fine distinctions and arguing over minute details.
* Pointless: This simply means the argument has no real value or purpose.
* Futile: This implies the argument is likely to be unproductive or unsuccessful.
The best word to use will depend on the context and the specific nature of the argument.