Variations on said, like answered, commented, added, replied, asked, queried, muttered, snarled, roared, are best used sparingly. They call attention to themselves and sometimes seem strained. Adverbs in speech tags often sound corny—she said kittenishly, he responded sneeringly, she hissed angrily.
An economical and effective way of tagging speech is to follow the line of dialogue with an action or a thought by the speaker:

“I’m surprised you came here.” Frank jumped up from his chair.
“I am too.” Eva looked past Frank, out the window, as if she did not want to admit that they were in the same room.

People speak variously. Some talk in clichés, some talk like the authors of philosophy tomes. Some people slip back and forth between dialect and formal language. Writers can signal that they know that the character’s speech is idiosyncratic:

Proget was a weird mix of garret and gutter. One minute he’d be holding forth about post-modern discontinuities and the next he’d be asking if you noticed the receptionist’s bazooms.

The result is that readers accept the peculiarity of the speech and, in fact, see it as a distinctive feature that helps establish the character.

Arguments are most nerve-wracking when the characters imply what they feel instead of coming right out and saying it. In fact, the more intense the feelings, the more likely people are to say the opposite of what they really mean. If you want to keep up a high level of tension, keep the dialogue evasive, filled with suppressed information and unstated emotions. Once people really are candid, once the unstated becomes stated, the tension is released, and the effect is cathartic. If you’re trying to build pressure, don’t take the lid off the pot.

Without sufficient eloquence, it’s a strategy likely to misfire into tendentiousness.