I drink de-caff mostly, because I get acid reflux and find that caffeine is one of the major triggers for me. I tend to think Yorkshire de-caff is the best I can find in terms of everyday brands in supermarkets, and although a bit weaker than "the real thing" it still gives a decent tea flavour.
I also buy regular teabags for those in the house who don't need de-caff and tend to switch between M&S Extra Strong, Typhoo (surprisingly good given how cheap it is) or Yorkshire for Hard Water.