Out of the X# I have at the moment, my females are better eaters. But only 1/4 of them are males so it's not really a fair comparison.
If you're only going to get one ball python, get one that you like the pattern and color of. The sex won't matter too much. But if you think you might breed someday, get a female first.
There's also the size thing, like Mykee said....