There's a couple threads dealing with this:
HELP! S4 or HTC ONE
Still indecisive! HTC One or S4, for overall convenience?
But remember that the S4 has a microSD slot. For only ~$20, you can get a 32GB microSD card for it.
If storage is the only thing that you're mostly concerned about, I'd go with the S4 unless you're sure that 32GB is enough for you.
Both are great devices, so there's not really a "WRONG" choice. Just one that is better suited to your preferences.