I currently have Wild Turkey's American Honey, Wild Turkey 101, Woodford Reserve, Jim Beam, Four Roses, and Bulleit bourbons. If I was to suggest one to a lady who found bourbons too sweet, I would start with the Bulleit. It's got a spicy flavor that also has a smooth finish.
But perhaps you'd try liquors mixed with fruit juices. Cape Codder (Vodka and cranberry), Screwdriver (Vodka and orange juice), a Salty Dog (vodka with grapefruit juice in a glass with a salted rim), a Tequila Sunrise (tequila over ice followed by orange juice with a floater of grenadine), and the previously mentioned Old Fashioned (muddle together a splash of Angostura bitters over a sugar cube with an orange slice and a cherry, then add the rocks and whiskey), or any of a thousand combinations of the four main liquors (vodka, gin, tequila, and whiskey) with any fruit juice. For variation, try a dark rum (start with Myers's since it is a richer flavor and it's inexpensive) with a citrus like orange juice.
When you get into the super premium tequilas, you're getting into sipping territory; it would be a shame to mix Herradura or Patron with anything but ice.
But that's typically going to be true of all premium liquor brands. However, I find that with vodkas, it's all about marketing since by definition, vodka should be odorless, tasteless, and colorless. This will certainly be disputed by those who will tell you that they prefer a certain brand. The last bottle of flavored vodka I bought was Three Olives' brand Dude. This was purported to taste like Mountain Dew (which I personally try to keep in business), yet tasted like glycol based anti freeze. I found that only when mixed with Sprite did it taste anything like the lemon-lime concoction from Pepsi and this made me wonder why I didn't just revert to my favorite college drink that I invented while working at a bar, the Dewdriver (vodka and Mountain Dew).
If you like a drier taste, perhaps a good gin would interest you. Most are flavored with juniper berries and other flavorings and run from dry to extremely dry. You could drink them as a Winston Churchill martini; fill the glass with ice cold gin and bow in the direction of France or as Alfred Hitchcock described it: The closest he wanted to get to the bottle of vermouth was to look at it from across the room. My favorite literary character, Travis McGee famously drank Boodles or Plymouth as his cocktail of choice.
I know you said you prefer to avoid liqueurs, but if you do go that route, there are some "less than true liquor" drinks you could order that you may find palatable and not be thought of as a nutjob for ordering. ("Bartender, I'll have two Pink Squirrels, a Grasshopper, and a golden Cadillac." This order was actually made to me by a burly British gent on holiday in Florida and I can still recall trying to stifle my laugh and refrain from the snide comment until, to my relief, he added, "and a lager.")
To that end, I would look at Brandy, Port, Sherry, Cognac, Armagnac, or even the lower proof things like the previously mentioned Drambuie (you could mix with whiskey and make a Rusty Nail), Grand Marnier, B&B (Benedictine and Brandy), Frangelico, or Ouzo. Most bars have these. They may have to knock the dust off of the bottle, but if they don't have it (or the bartender doesn't have the faintest clue how to make the drink if you do decide to settle for the Pink Squirrel) I would deem them not worthy of the name "bar" nor the tender worthy of the title and leave.
But I've bartended a long time and I may be a snob about this.