I like all of their teas, regardless of price. I actually prefer the more modestly priced senchas, like Unro and Nichi-getsu, as a refreshing morning tea. But yeah, their high-end senchas and gyos are sublime. Kaboku sencha and Kanro gyokuro (as well as Tenka-ichi) are personal favorites, when I have the time to slow down and appreciate the depth of flavor. You might want to check out the gift set sencha/gyo combos.
Almost forgot; if you are a fan of roasted tea, be sure to get at least one bag of hojicha (or kuki hojicha). Hands down the best I've ever had. Unbelievable aroma that fills the room!