I put taste on top because no matter how fabulous a tea smells, if the taste is too bitter, I won't be able to enjoy it. Taste can sink an otherwise amazing tea experience for me. At the same time, an amazing smell is the key to lifting many tea experiences from good to great, and the sense of taste is mostly smell anyway.
Thursday was a good tea day for both taste and smell: a starter thermos of Sea Dyke Tie Guan Yin, toasty and warm and comforting, and then several teas with a stronger scent component--some Jade pole green tea from Yunnan Sourcing, and the amazing citrus-fresh Ye Sheng Wild tea log from Norbu.
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I vote for sense of smell. The scent of the tea is most important. A tea may taste fine, but if I dislike the smell of it, then it is not enjoyable to me. I agree that scent and taste are intertwined, so a tea that smells great makes it taste that much better. I was drinking some very nicely scented and tasty shan lin xi today from TFT.