I like coffee shops too, but I feel pretty bad about taking up tables and not buying coffee. So on days when I feel cheap, I'll just go to the library. On days when I feel like spending money I'll go to a coffee shop and buy a few cups (or one cup and put some money in the tip jar).
Funnily enough, I also enjoy the atmosphere/noise of a coffeeshop. I even once went looking to see if there were CDs or streams of coffee shop noise in order to try to emulate that effect without actually being in one. Unfortunately my search yielded no results!