There are a lot of teas available, falling in the basic broad categories of black, green, and white. I've learned through experience that I like basic black teas. In the commercial brands, my favorite is probably Stash (which, coincidentally enough, is made here in Portland, Oregon). I love their English Breakfast and their Irish Breakfast, both of which are basic black tea blends. I also like their "Fusion", which is a green/white blend that doesn't have an awful lot of flavor. Even your basic Lipton tea appeals to my palette.
Because I spend a lot of time at Starbucks, I also discovered some of the Tazo teas. Their Awake black tea is one of my top three as well, but most of the rest of the Tazo leaf teas are just too weird.
For folks who like tea, I would recommend a visit to www.mycupoftea.com. Besides having a great variety of leaf tea, they also have a wonderful introduction to tea varieties and tea growing. I ordered three bags of loose black tea from them ("Trafalgar English Breakfast", "Assam" from India, and "Chinese Keemun"); all three are very, very nice. The quality and clarity of flavor are clearly better than the bagged tea I've been buying, and I find that the hassle of using the infuser isn't that much greater than using a tea bag.
I was pleased to learn that my latest contract is located in a building with a lunchroom stocked with about 15 different kinds of tea, and TWO refrigerators with ice makers. I can make myself REAL iced tea twice a day, and it's much better AND cheaper than hitting the Coke machine.