I've had a few job interviews recently and I seriously wonder what exactly should I say when they ask me about my motivation for looking for a new job.

I completely avoided talking about money except when they ask for my desired salary, even though I'm currently underpaid because of company-wide pay freeze.

I talked freely about how I don't like my work environment - small, isolated team. I also talked quite openly about wanting to work with more up-to-date technologies.  But in retrospect even these reasons can discourage people from hiring me if they think they can't provide exactly what I'm asking for.

On the other hand, one has to say something to not appear like they're running from trouble etc.

So topics should I focus on and what should I avoid talking about?