I only drink coffee for the kick in the morning, I drink tea the rest of the time.
I'm a big fan of any number of Oolong teas, hard to go wrong just picking one and trying it.
For black teas I like Yunnan Gold, Darjeeling and Assam the best.
Green tea: anything sencha. Green tea is much more subtle and less forgiving to brew. I generally would rather have a good oolong (somewhere between green and black).
In the evenings I tend to drink rooibos (red) tea or perhaps a decaf black tea.
Just try to find some good black teas to start and stay away from Teavana's overpriced stuff. Peruse Republic of Tea, Arbor Tea, etc. for a good selection of affordable teas and go nuts. Try to get full loose leaf tea if you can, the quality is far superior to bagged tea.