Home-brewed tea is DEFINITELY better than soda. Not just on a calorie counting basis. The chemicals in soda and their side effects could make your head spin. They're even worse in diet soda because you add aspartame to the equation.
I used to have a serious caffeine/diet soda addiction. (I would get intolerable migraines when I would try to give them up.) I gave it up on my wedding day. It was easy because we had sweet (brewed) tea at the wedding, and the week of our honeymoon we didn't stock the cabin fridge with soda. I just drank water or tea that entire week. When I got home, I thought
Why not give it up for good now that you've gone a week without it? And I did! I haven't had one sip of soda (diet or regular) since May 2010.
There are so many different kinds of tea out there. (Someone here mentioned putting milk in tea. Wha???) In the southern US, we love our sweet tea. Since it's high calorie, I get unsweet tea and add no calorie (and no aspartame) sweetener to it.
But 99% of the time, I drink water. I only drink tea on the (RARE) occasion that we go out to eat. (Tap water - ick.) If you can, you should be drinking plenty of water. If you don't like water, try the flavor packets. I tried Crystal Lite's strawberry flavor packet (actually took a sip of my mom's) this week - it tastes like Kool-aid! I drink anywhere from 72 to 96 ounces of water a day. Love it!