Top Gin
Dang! I saw this article, The 8 Best Bottles Of Gin You Can Buy At Any Price Point, glanced at the picture and thought, "Wow, I've owned and drank every one of those bottles at least once." But then I noticed one of the bottles is Aviation Gin, which I've never tried.
The top six are strong selections, but the article is snobbishly misleading. It says "any price point," but they mean, "any price point mid-shelf and higher." It offers no lower mid-shelf or low shelf options.
For the lower mid-shelf, I strongly suggest New Amsterdam gin. This gin is one of my favorites, period. And combined with Fever Tree tonic? You'd need a very discerning palate to notice a difference from, say, Hendrick's. Of course, I suppose the very discerning palate doesn't use tonic at all, but if you like a solid gin and tonic for a reasonable price, I definitely endorse New Amsterdam, especially if you like the western style gins.
For lower shelf? I'm afraid I don't have much experience, but a friend of mine once served me Kirkland's Dry Gin, and it was fine. Like Sam's Club's Member's Mark liquors (notice the possessive trifecta), Costco produces big bottles of good liquor. None of it will blow you away, but if you're merely looking for a mixer, I highly recommend them. I keep a few giant bottles of Sam's American Vodka on hand at all times. It's my "go to" vodka when I need to entertain more than a handful of guests.
If your guests are snobs, you can pour the American Vodka into an empty Grey Goose bottle. They won't notice the difference. If you don't feel comfortable with such deception (I've never done it, though I've been tempted), consider cut glass decanters. Those make every beverage look appealing.