I use Fantastic wipes (green soft package) on my bikes. It says it's okay for bikes and I haven't seen it do any harm for just light cleaning. I use it on both my ti (unpainted) and aluminum (painted) bikes.
I've also heard that 409 wipes (orange, especially) are really good - but that was from someone who also has an unpainted ti bike. I couldn't find them at the store, which is why I got the Fantastic ones.