Companion planting is a great benefit for the gardener and the garden! There are many traditional combinations that work together in harmony for benefits like physical protection (from wind, harsh sun, trellis / support, weed suppression), pollinator attraction (flowers!), pest repellent / trapping (aromatic plants!), and flavour / quality enhancement through an increase in soil fertility and overall plant health! From a few different online garden resources, and from my own experience, these are some tried and true garden buddies.
Overall good to include in your garden to repel pesky insects and attract beneficial ones:
Mint
Thyme
Chives
Nasturtium
Catnip
Sweet Alyssum
Borage
Cosmos
Calendula
Dill
Marjoram
Oregano
Enhanced flavour and vitality:
Basil + Tomatoes
Parsley + Tomatoes
Strawberries + Borage
Strawberries + Thyme
Zucchini / Cucumber / Squash + Nasturtium
Zinnias + Zucchini
Beans + Corn
Beans, Squash, + Corn (referred to as The Three Sisters by some Indigenous North American peoples)
Lovage + Beans
Beans + Potatoes
Calendula + Broccoli
Radishes + Carrots
Chives + Carrots
Cabbage + Sage
Dill + Cabbage
Basil + Purslane
Chamomile + Onions
Cilantro + Spinach
Garlic + Roses