2-3 diet sodas (depending on can or bottle, generally), and usually a glass of milk at some point. Rest of my consumption is water or water with some sort of flavoring like Mio or Crystal Light.
I used to drink a lot of soda but now it's just water and I'm feeling great. I've lost 20 lbs just by doing that and cutting down on the fast food. Lay off the soda guys, it's no good.