Depends on the time of year. As a rule I like cask strength iterations of Laphroig, Aberlour, & Macallan because of the relative weight savings vs a typical 40-43% offering. Laphroig is great in cold weather because of its heavily peated nature that just feels "warmer" going down;) I find Lowland malts nicer in the warmer months because they are less heavily bodied & more crisp, grassy, lemony ie. Bladnoch or Auchentoshan. My overall favorites, I think, are the offerings from Macallan. The Macallan 25 YO Anniversary offering is so good that I can't believe it is crafted by the hands of mere mortals!
For all you single malt enthusiasts wanting to try something new, try the Japanese malts from Yamazaki (12 YO, 18 YO). They are not legally "Scotch" but surprisingly good.