The poll is kinda confusing as all of the above are whiskey/whisky!
Do you mean Tennessee whiskey as just plain "whiskey"? There are two distillers that do that last I checked, Jack Daniel's and George Dickel (my favorite). There's one extra step involving filtering for TN whiskey, but it is generally very, very similar to an average Kentucky bourbon whiskey. Put it this way there are bourbons that are more like JD than they are to certain other bourbons.
I know there are some "American whiskies" that exist, that are brewed outside of TN or KY, but there aren't that many and they don't have a large shared amount of unique shared characteristics to really be their own style, more just outliers.
Canadian whisky has the e-less spelling and I don't know a lot about it. I've had some that's quite good, but more that I've tried is just mundane and watery. But I haven't tried many top-shelf examples.
Scotch whisky (the other one to lose the e) is my favorite at least in single malts. Sort of the varietal wine of the whisk[e]y world. Aberlour (10yr and a'bunadh) and some of the Islay malts are my favorites, although they could hardly be more different.
Irish whiskey has a sort of pleasing spiced sweetness to it...like a more easily drinkable version of Scotch whisky. Black Bush has a nice pear note that is really nice.
One other question...you mention rye being too sweet...you're not talking about "Rock and Rye" which is a liqueur, right? Rye whiskey is similar to bourbon but made with a larger proportion of rye in the mash. Spicy is the usual descriptor, I've never thought of it as sweet but then again, taste buds are unique. Rock and Rye on the other hand will be actually sweetened.