According to Wikipedia, over 7,500 apple cultivars have been developed. New cultivars are bred for taste, but, also, for disease resistance and productivity.
One old apple variety, Rambo, was brought here from Sweden in 1643 by Peter Rambo, my 8th great-grandfather. Rambo apple trees are still available from specialty nurseries, but the apples are not for sale in grocery stores anymore.
Among newfangled apples, Costco carries Fuji. To me, Fuji apples are the perfect mix of not too sweet and not too tart. (Costco carries many other varieties, if you prefer those.)
Fuji (or other) Apple Waldorf Salad
1 Fuji apple chopped
2 sticks celery chopped
1/4 cup raisins
1/4 Kirkland Sahale snacks (or walnuts)
1/4 cup mayonnaise
Stir together and chill. Using the Kirkland Sahale snacks as a substitute for walnuts worked great; any crunchy nuts would work.