I agree with Denis’ question, as the answer to that might strongly influence any answers.
If he enjoys the parlour game of guessing, then there are lots of options, but for me the sneaky fun option might be to have 6 wines, but where there is also a common thread to all of them, be that a region, family wineries, wines from > 100 year old wineries, the same vintage and so on. As well as having a go at guessing the individual wines, there is another common link to work out. It shows a bit off thought / effort.
On the other hand, some wine enthusiasts don’t really care for the parlour game. A nice considered selection of wines, be it with a common theme or not, would be most appreciated.
It’s good if you know their interests, for instance some enthusiasts despise Sauvignon Blanc, or are very particular about chardonnay styles. Indeed many of us would most enjoy being offered some more obscure wines / grapes, but perhaps with a nice safe stalwart to finish. I’d lean this way if I didn’t know their tastes.
One alternative on the simple guessing game, is ‘options’. Everyone plays, and each wine has ~ 3 questions, each of which has 3 multiple choice options. A correct guess earns 1 point
e.g. Wine A
Q1: Is this a 2005, 2007 or 2010 vintage
Q2: Is the wine 14% alc , 14.5% alc or 15% alc
Q3: Is this wine from Washington State, Sonoma or South Australia
Wine 2
Q1: Is the lead grape Semillon, Sauvignon Blanc or Chenin Blanc
Q2: as it aged in American oak, French oak, or stainless steel
Q3: Did Parker score this wine 90, 92 or 96 points?
You don’t have to rigidly stick to 3 questions / 3 answers of course, and ideally most questions can be derived from the front or back label (for ease, but I suppose to avoid disputes!). You can stick to the same 3 questions e.g. Grape / region / vintage, but I’d lean towards mixing the questions up a bit.
regards
Ian