Lime flavored Perrier is delicious, but too expensive. Ditto La Croix’s peach ginger flavor. Ditto all of LaCroix, in fact.
The Safeway house brand (Refreshe) has a lot of flavors (grapefruit is my fave) but the flavoring isn’t as strong as I’d like. It’s faded out by the time I’m halfway down the can.
Schweppes’ black cherry seltzer is my absolute favorite, but it’s difficult to find when out and about.
Canada Dry mixed berry seltzer is a barely-adequate substitute for Schweppes, but more easily found.
Arrowhead is tasty enough, but a bit too… burpy. The carbonation is a little over-enthusiastic, I guess.