Though I just use bags in individual cups at work, on the weekends I like to brew a whole pot, with loose leaves, if I can. I can't really tell any difference in taste. And it almost doesn't matter what blend it is - though my absolute favorite so far is Twinings Irish Breakfast. It's power, I think, lies in the ritual of making it. The tiny, mindful steps are a guided meditation of sorts:
Filling up a teakettle. Heating it on the stove. Gathering the incidentals (lemon? honey? yes, please). Measuring out the tea. Waiting for the kettle's whistle. Slowly pouring water over the leaves. Watching the tea darken. Steeping for an intuitively decided amount of time. Pouring a cup. Waiting for it to cool just enough.
That process is powerful. Conjuring up the memory of that process at least twice a day at work is powerful. It slows you down. It makes you focus. And it can hypnotize you, if you let it.
Or is that just me?