I despise bottled salad dressing. I grew up during the era of fat free Italian salad dressing, and I can remember the taste clearly: powdered onion/garlic flavor, combined with a sickly sweet undertone of sugar or corn syrup, dehyrated vegetable flakes, some preservatives and additives, all held together with soybean or canola oil. No wonder many people don't care for salad.
Salad dressing has become like mayonnaise, meaning that it is one of those food products that people don't make from scratch anymore. It doesn't even occur to people that you can make it because the food industry long ago convinced us that it is just too much bother. But homemade salad dressing can be as easy as mixing some oil and vinegar (or citrus juice or some other acid) in a tupperware container, and giving it a good shake to emulsify.
Adding a finely diced (or even coarsely chopped if you're lazy) shallot to the vinegar will take the salad to another level. I throw the shallot pieces into the container and cover them with the vinegar or citrus juice. After adding a generous pinch of salt, it is best to let the mixture emotionally sit in order to lightly pickle the shallot, mellowing out that oniony bite. Finally, mix the shallot and acid mixture with 3 or 4 times as much oil, grind some fresh pepper into it, place the lid on the container, and shake it to emulsify.
This dressing happened to be walnut oil and sherry vinegar, but you can make a delicious dressing with simpler ingredients like olive oil and lemon juice. It will be free of unnecessary additives muddling the flavor, and it will taste brighter and more pure than anything you can buy at the store.