The best is, of course, what is best for ones taste.
I am relatively new to scotches, but this internet is a great source of education, scotch or otherwise.
I got introduced to the drink about a month ago (I drink bourbon occasionally) by my son-in-law. Since then I have scorched a trail in the scotch internet-world, and my budget.
He got me a shot of McCallan fine oak 15 year old, and was impressed with the smell (I say "smell" because I am a newbie). I liked the "taste", and the alcohol was not intolerable on my mouth, hard and soft palate, and nasopharynx. I was quite impressed by it, really, that I bought a bottle the next day.
The next night I had 30 cc of my new bottle, but somehow it did not "taste" as good as the first time. I changed the drinking glass to about the same kind used at the restaurant, but that did not change the "taste".
So I came to the conclusion that the pleasure of the first experience was modified by at least a few changeable factors:
1. One's state of hydration
2. The electrolyte balance (sodium, potassium, chloride)
3. The temperature and humidity of the room.
4. Other subtle factors that I may not be aware of that changes the sensitivity of the olfactory and taste functions in any given time.
So my quest on a constant or near constant pleasing taste to my now new drink - scotch - would have to be a new blend. My own blend.
So I bought a few bottles to modify the base taste of my Macallan.
I got a peaty, smoky, islay.
I got a sweetish Crown Royal Maple Finish and a more peaty Hazelburnhttps: 8 year old finished in sauternes cask.
And just for the heck of it, a bourbon finished in portwine cask.
Finally a relatively "bland" irish blend.
So now, on any given evening, when I want to modify the 15 year old base scotch, I can add a bit of peat, smoke, sweetness.
And even if I do not really get the finest of result, I use my imagination that I have done so.
I guess it all goes back to basics - a matter of taste.