Well, if you like tea or know someone who likes tea or maybe you'd like to drink more tea the UK could serve you well. Being a big fan of tea myself I have two favorite shops in London. One very British (Whittard) and the other very Australian (T2). One very traditional and classic (Whittard) and the other very modern and funky (T2). BOTH have perfect, smooth blends, amazing shops and very friendly and attentive employees.
Whittard also sells pretty good coffee, a smooth hot chocolate, biscuits (cookies), mugs, tea pots and tools. T2 also sells amazing mugs, tea pots, tea tools and tins. BOTH have great packaging which makes it for such a great gift from your travels. BOTH brands are present in other countries and have a nice on-line presence. So, good idea to check their websites to find the best way to shop their produce.
Enough said. Hope the galleries below help you make a decision (or maybe not!). I usually visit both for my tea :)
First, T2 shop: modern, beautiful colors, amazing wrapping paper!
And Whittard experience: tradition and classic flavors.