Peach is my favorite flavor for iced tea. I made a signature blend of white peach and peach oolong called "Life's a Peach" and it's good hot and fabulous iced. Another interesting iced tea signature blend is Tequila Sunrise... a combo of white teas and blood orange... very nummy. Warm Smell of Colitas is very good iced as well. Sorry for self-promoting, but these are the blends I know best because I created them around my own preferences.
I made a decaff tisane signature blend in honor of the Twilight movie that has been really popular, called #1 Freakin Twilight Fan... wild strawberry, cherry, and blood orange, to make a nice red brew for all those blood-lust people.
I also really like iced Moroccan Mint or Casablanca Twist... very refreshing. And my most common choice for iced tea is an unflavored darjeeling or oolong, because i just love those flavors so much.