Highland Park is always a good choice, I really like ardbeg too, Talisker but laphroag has a pretty specific finish that I've tried (I really tried :) ) but can't get on with. Try Smokehead and also anCnoc
royalmilewhiskies is a really good site (and a real shop if you ever go to edinburgh (stanes and malt weekend anyone)) and will give you lots of ideas as well as explaining about the differences
tesco own brand 12yo islay, I'm convinced it's bunnahabain ;)