What's the best ammo for a 9mm handgun?

Take a look around the forum, there are plenty of threads about that.

But each ammo has its purpose and it what gun also matters

Whadda you wanna use it for????

For trigger therapy, the lowest cost on the shelf, I like WPA steel case, Aguilla brass, Blazer aluminum case.

For HD/SD, don't be penny wise, but pound foolish. Hornady, Federal, Cor Bon, are a few, not all, to consider.

Most any should work for the range, some just require more cleaning time when you get home.

Ammo selection is like spouse selection. Everyone likes something different.

By this standard I'd have a new wife every couple of weeks. I'm more habitual with my ammo selection than I am with my girls. Eesh... perish the thought. Lol

I was wondering for target practice and home protection.

Do a little reading here- Its all over the place "this vs that" -

Just make sure you stuff some hard peas in that peashooter.

What Hoss said. Also depends what your gun likes to eat for dinner. My Glock 19 isn't a picky eater. I have another 9mm that is a bit eccentric.