This time last year I put together this collection of whiskies, which did a pretty decent job of providing a sampling of the different regions:
My only Lowland was a Battlehill bottling of Auchentoshan. That was enough, as I did not expect to enjoy the Lowland flavor profile, and sure enough, I didn't. I still have that same bottle, and probably will for a LONG time!
I divided the Highlands into those with a wood finish and those without, as the flavor added by a sherry cask (or other wood) is noticed. I thought this was a more meaningful division than those in the Speyside region and those outside.
Sherried (or other wood finish): Macallan 12, Glenfarclas 10, Aberlour 12, and Balvenie 12 Doublewood would all be excellent examples of these. The Macallan 12 is only slightly sherried, while the others have a more distinctive taste.
Non-sherried: Balvenie 15 and Glenrothes Select Reserve, would be good examples of these.
To represent the Islays, I had Laphroaig (lower in peat, heavier in iodine and smoke), Bowmore (heavy peat, no iodine or brine), and Lagavulin (perfectly balanced mix of the Islay's flavors.)
Campbeltown is represented by Springbank.
In addition to these, there are a host of other islands you could represent, that don't necessarily have their own region named for them, but are just grouped into "Islands". These would include Highland Park on the Isle of Scapa, Tobermory on the Isle of Mull, Jura on the Isle of Jura, Isle of Arran, Talisker on the Isle of Skye.
As subsets of the above, you could do Western Highlands to include Oban, Northern Highlands to include Glenmorangie, and of course Speyside which would include Glenfiddich, Balvenie, and Macallan.