What should I say in this job interview?

In interviews my rule is always never say something bad about your previous job. But try to find something better in the company you're applying. As if : "There's nothing crucial about my previous company, but i've been working there for 9 years and i found no improvements lately. I'm sure i could found a better opportunity here (in the company you're applying) as your company is a well know for blah blah blah (show them that their company is better by not putting down your current company)... That's the way i do it. :)