Having seen a ghost, and never seen a zombie, I'd say the odds of seeing a ghost are higher, therefore making them more terrifying (at least for me).

Ghosts may not be able to eat your brains or tear off your arm and beat you to death with it, but they have been known to throw people down stairs and sort of follow their victims everywhere, sometimes even haunting them for life. I've seen about ten ghosts in my life, in several states and countries. And I do not look forward to the day I see one again. Ghosts, hands down.

Not to mention, zombies are kind of dumb and they live on the same dimension as humans, making them more predictable and easier to defeat. With ghosts, you just never know what's coming next.

Zombies are bound by things like gravity, and an inability to just magically appear through a wall.

On the other hand, as Pyg pointed out, at the end of the day, a ghost couldn't do much accept follow you around all day and make noise I guess.

Which while scary for it's weirdness initially, would soon only become boring and annoying - while zombies apparently have some kind of weird craving for human brains, which is far more dangerous I think, than just kind of hanging around.

That said though again, you could just hit a zombie with a shovel or something.

I know that ghost are real. During my cousin's funeral, the lights kept flickering on and off. The priest said that it was her spirit bidding one last far well.

It depends which type of ghost, of course! If its the ghost that just moves around scaring people with its presence, then not so scary. A zombie could do more damage than that.

But, if the ghost is the kind that you may not be able to see and has the mysterious ability to make things on shelves come down, move things, and make furniture fly across rooms, then that is pretty scary. You can't necessarily see that ghost, so you might not know where it is. The ghost can throw things at you with no warning, so that would unfortunate. And, when you do know where it is, you can't hit it with anything, so it would be very difficult to make the ghost stop terrorizing you, unless you are dealing with an empathetic, reasonable ghost, and you have the ability to persuade the ghost to stop.

Still, ghosts are scarier.

Zombies can be cured by a bullet to the brain... ghosts are a little more tricky.

Ghost are more scarier then zombies because 1 their real, 2 they can frighting you until you wish you were dead instead of actually killing you, and 3 it is scary to know that one day you may become one two.