Here's a few suggestions from me...

Almdudler (Austria's National Drink) available at World Market Almdudler

Several of the beverages at IKEA are also great. I usually pick up a few cans of the ciders (both pear and apple) but the concentrates are good as well. IKEA Beverages

I also like the Ito En bottled teas. I don't like sweet tea and these are all unsweetened. You can find them in Whole Foods. I get excited when I can find the 2L bottles. Ito En

Generally, I'm drinking either San Pellegrino or Poland Spring sparkling waters. Plain old water just doesn't do it for me.