In the last two trimesters, I pretty much stuck with plain old water, and a cup of coffee a day (my cup of coffee is really 1/3 coffee, 2/3 milk). But when I had morning sickness, I pretty much lived on seltzer. I actually drank Coke, which is bad for you more than the fetus I think. The bubbles calmed my stomach, the "sugar" was about the only calories I could keep down in a day, and the caffeine kept me going through meetings when I hadn't slept. It's terribly unhealthy, but when you're desperate, you'll go with whatever you can keep down.
I think people are a lot more cautious about what pregnant women eat and drink than is necessary. Beyond living at Starbucks or lining up shots, your body should process out most of the bad stuff. Of course, *you* are the one who will suffer for that, so it's still a good idea to stick with healthy drinks and foods.