Thanks for all your replies. Some great advice there, and I've added a few to my shopping list for next time.
The ones I have tried so far are:
Kendal American Delite - at first I could taste nothing, but this one has really grown on me. My second fav after London Mix.
Peterson's Sweet Kilarney - didn't like the first bowl, very sweet, but quite enjoyed a bowl this morning.
Savenilli Aroma - Quite liked this one.
The ones below all get rave reviews online, but to be honest I can't distinguish much between them:
MacBaren 7 Seas Cherry
MacBaren Vanilla Cream
Peterson's Connoisseur's Choice
The ones I definitely wasn't so keen on:
St Bruno (popular UK tobacco - but to be honest it didn't do it for me).
Sam Gawith Christmas 2014 (just didn't get any Christmassy taste)!
I expect in time some of these will grow on me. Like many newbies, I have opted mostly for aromatics, but my clear preference for the Dunhill London Mix above the others may indicate that I quite like something a little more robust. Given that, I have ordered some sample packs of various Dunhills, which should arrive on Tuesday: De Luxe Navy Rolls, Early Morning Pipe, Elizabethan Mixture, 965,Nightcap, Royal Yacht.
Not sure which to try first or what to expect! I'll let you know how I get on.