My concerns about powerful emotional descriptions are twofold:
(1) People often aren't aware of powerful emotions at the time they experience them. A man who is stomping around the room, shouting and pounding the table, may respond to a statement of "You're shouting" with an emphatic (and sincere) "No I'm not!". The frantic old woman calling the fire department with hands shaking so much she nearly drops the phone might respond to an injunction to "calm down" by thinking What do you mean? I'm perfectly calm.
This makes it difficult to describe the emotions of your viewpoint character because he or she is unlikely to be paying attention to them; his or her thoughts are completely consumed by something else -- usually a goal or a fear.
It may be preferable to leave emotional descriptors out of the conflict itself and bring them back in only during the aftermath, when the character begins to notice his emotional state. He may then consciously unclench his fists or lower the volume of his voice.
(2) The most commonly abused melodramatic descriptors carry no sensory data.
Consider the following:
"Dan clenched his fists, furious at Theresa. She glared back at him, obviously unwilling to hand over the cat."
Now, this is perfectly acceptable prose that might happily find itself nestled within any number of stories. However: an entire page -- or even paragraph -- of stuff like this is going to begin to feel flat. Why? Because it's relying almost entirely on the reader for sensory data.
What does it look like when someone glares? Not sure, but I kind of know how to picture it. How about clenched fists? Well, ok, I know what position they're in, but not really what they look or feel like. You're the author. It's your job to make me see it. To pick out details that will make me experience the scene in ways I would never have managed if left to my own resources.
Again: The prose above is perfectly fine and has its uses, but if you want to hilight the emotional aspects of a scene without triggering my melodrama alarms, you're going to have to get more inventive.