I second Ray's scotch prowess. He's steered me right on more than one occasion.
I often enjoy whiskies (including blended scotches) on the rocks but I prefer my singles without ice. While adding water often opens up some flavors, chilling can dull others.
As do some kindred spirits here (no pun intended) I much prefer the Islay malts...Lagavulin 16, Laphroaig 10/15, and Caol Ila 18 are favorites. I also enjoy Talisker , from the only distillery on the Isle of Skye (the Highlands), similar in style to the Islay malts but with a more pronounced, medicinal character. Then there's the old standby, the Glenlivet...especially the 18- and 21-year-old expressions. But there's also Ardbeg, Oban, Scapa, Glenmorangie, Aberlour...too many to mention.