My favorite is 12 y/o Glenlivet (my Scots-American buddy, though, loves Glen Morangie). I have also been told that REAL Scots Scotch drinkers prefer 12 y/o to 18 or higher because the complexities and flavors age-out though they do become smoother.
Glinlivet is a “sure thing” though as the first bottle I of scotch I ever bought (single malt at that, IIRC) it was a harsh training ground and so I have a hard time going back to it as a bottle purchase. LOL