Guys need at least some armpit hair. None looks odd (and itches afterwards). Too much makes you look like an environmental activist who's into tree-hugging and lentils. If you have an electric shaver with a trimmer facility, when you're dry, lightly skim the hair so it's cut down to an inch or less.
I remember when I was at university in Germany. The Greenpeace girls had armpit hair longer than my head hair. There was a joke at the time, you can tell a Lufthansa plane because it has hair under the wings.
Trim it, but in moderation.