At work right now and here it is usually coffee or water.
Right now I am having decaffeinated instant coffee with a bit of cocoa powder added (the plain stuff, not the sugary thing) and a bit of milk. While I usually drink regular black coffee, I like to spice it up in various ways from time to time. The flavors of ground cocoa and coffee goes along very well in my opinion and cocoa should even have several health benefits as long as you can drink it without sugar.
Like coffee, the bitter taste of pure cocoa is an acquired taste but not one that is harder to acquire than for coffee in my opinion. Once you get the hang of it it is very nice indeed and hard to live without, just like coffee.
If you go cold turkey from caffeine, it should not take more than about one week before you should be rid of all the symptoms. While it may feel bad during that week, it is quite easy and quick to kick compared to nicotine-addiction etc. While I do drink coffee most days, I am unsure just how addicted I am to caffeine. Some times I can go a couple of days without having coffee without any adverse effects. I get most of my coffee at work, so during the weekends it happens regularly that I don't drink any between Friday and Monday.