"Why do you want to leave your current job?"
There are many wrong answers to this question. Some of them include saying things like, I hate my job, I hate the company, I'm not appreciated there, I hate my boss, I'm sick of working there, etc. Basically, anything negative is a bad answer. If you say something negative, they will think you will eventually get into that situation again while working for them. So I highly recommend you have a good answer that leaves a positive impression while displaying good traits.
Short Answers
"I want to find a company with more opportunities. My previous company was very small and didn't have opportunities for growth. After learning about the work environment here, I felt this is exactly the type of place I want to work."
"My current company is very large and it's difficult to do different tasks. We have routine work that never changes. I want to work in an environment where I can utilize more of my skills."
"Our family moved to live near a better school district for our children. This area is great and I want to find a job closer to my new home. My previous job was too far away to commute."
Long Answer
"I really enjoy what I'm doing, but I feel I'm following a routine. I looked around for more opportunities to grow, but because the company is small, I'm very limited. I want to work in an environment that will help me realize my full potential and a place I can contribute everything I'm capable of doing. My current job doesn't provide these things for me and that's why I want to work here. I know ABC Company has a lot of opportunities for growth and encourages employees to take on challenging projects to learn more. That is what I'm looking for."
This answer shows a couple of good traits. It also shows excitement and mentions the company name. It is personal and direct. This is a generic answer so you can use this if you want. If you decide to think of your own, make sure it displays good traits and the reason for wanting to leave your current job is not a negative reason.