some more info on regional differences for the single malts:
http://www.scotchwhisky.com/english/about/malts/index.htm
http://www.sohowhisky.com/regions.asp

I’m more a Speyside guy. Enjoy Highlands and Lowlands too, but Islay is too peaty for my palate. The beauty of Scotch, is that there is such a wide variety, anyone can find one that suits them best with a little bit of hunting and experimentation.

happy hunting. and happy experimentation (the best part)!

You can go to this website and get some good info.

http://www.discovering-distilleries.com/

I do enjoy a good scotch so for starters, consider the price. The really top shelf:Glencinchne,Glenmorangie, Talisker, Oban, Laphroig Dahlwinnie to name a few. I particularly like the stuff from Islay.

most, if not all, Scotch is double distilled. Distilling is simply heating the liquid and capturing the vaporized alcohol, which cools in the coils, turns back into liquid and is recollected at the end of the coils. You can do this several times if you wish. Vodka is typically triple distilled.

Scotch, as all distilled spirits, begins as a clear alcohol liquid. Scotch gets it’s color, and flavor, from the barrels. It retains more flavor from the fermented mash by being distilled at a lower proof and being less thoroughly filtered than that of vodka or gin.

To really find out what your colleague enjoys, a quick discussion about the regions from which he likes to get scotch from, will be most helpful. If he doesn’t know the regional differences, he probably drinks blended Scotch. Johnny Walker Black is a good buy.