Flip, I think the most important question here is, what does your son currently enjoy?? Being new or not really knowing is a valid answer, too. So much variety that you could give him the most expensive Islay scotch on the market and he'll hate it if he doesn't care for that style.
last couple of bottles I've given to him and
my daughters husband, they all enjoyed. but I am note sure
if Seth is still at Shoppers vineyard(he used to recommend good scotch).
One bottle was Monkey Shoulder, others were a Johnie Walker sampler,
he does like the platinum and the blue.
And, of course, there are always those who turn up their noses at Johnnie Walker, which is absurd. It's okay to not like a particular blend, or to prefer single malts, or whatever. Your taste buds, your choice. But to insult the blends as somehow genetically inferior to the single malts is absurd, since Johnny Walker is made from them. If I recall correctly, Macallan figures heavily in all the JW blends, with Talisker a close second and a major component of the Double Black and the Green Label. And since the blends all consist of dozens of sources, it's statistically likely that anyone's particular favorite single malt is in there somewhere.
A few weeks ago I was at a herf drinking some really good scotch, and some yahoo tagalong started waxing poetic about how single malt is scotch in its most pure, historic form. The boy obviously didn't know his whiskey history...or science.