Fragaria ananassa. Full Sun Soil pH: 5.5 to 6.5
Best Companions Borage - Spinach - Beans
"Companion Planting is the growing together of all those elements and beings that encourage life and growth; the creation of a microcosm that includes vegetables, fruits, trees, bushes, wheat, flowers, weeds, birds, soil, microorganisms, water, nutrients, insects, toads, spiders, and chickens." - John Jeavons, How to Grow More Vegetables Than You Ever Thought Possible
Do Not plant strawberries near members of the cabbage family which inhibits their growth. This includes broccoli, cauliflower, Brussels sprouts, cabbage, collard greens, kale, and kohlrabi.
Borage : This flowering herb attracts pollinators as well as beneficial insects that prey on many strawberry pests. It adds trace minerals to the soil . Some people claim that the flavor of strawberries is enhanced when grown near Borage.
Planting borage with strawberries may also increase the yield of fruit. Borage has limited culinary use which is perhaps why it is not commonly grown in edible gardens.The borage flower is sometimes used as a garnish and in potpourris. Occasionally it is candied.
Borage plants do add small levels of trace minerals to the soil in which they are planted which is beneficial not only to the strawberries, but most other plants grown nearby.
Caraway attracts parasitic wasps and other beneficial insects that feed on some strawberry pests.
"corriander and caraway attract parasitic wasps, spiders, hover flies, lacewings and ladybirds" The Best of Growing Edge Vol. 2
Certain plants release a compound known as hexenol, which parasitic wasps and other predatory / beneficial insects are drawn to, it works as a natural defense against insects.  
Lettuce apparently does well with strawberries, the mechanism behind their symbiosis is unclear.
Spinach can be amicably grown with strawberries, they draw nutrients from different soil levels and don't compete with each other, the spinach grows taller and will provide partial shade for strawberries. The strawberries benefit from the anti-fungal / bacterial properties of Spinach. "One attribute of Spinach is that it produces and a substance known as saponin... Strawberries are known to benefit from this." Carrots Love Tomatoes - L. Riotte Pg.7
One variety of Spinach I grow in portions of my Strawberry patch is Strawberry Spinach.It produces Spinach , as well as edible berries. It is more heat tolerant than common spinach and is available in warmer weather when other spinach plants are not producing.
Bush Beans are Nitrogen Fixers, and will add to improving strawberry growth and yields. They are also believed to repel certain beetles which are pests of strawberries, although this is not proven beyond the shadow of a doubt.
"Bush beans planted with strawberries also help one another, both advancing more rapidly than if planted alone." Carrots Love Tomatoes- L.Riotte
Lupin is an attractive flowering legume that produces lupin beans, more commonly used in Mediterranean cuisine. Like all beans, lupine fixes nitrogen in the soil. Its flowers also attract pollinators which serves as a double benefit to Strawberries and other neighboring plants.
A few other plants that attract pollinators and have no known antagonistic relationship with strawberries are Yarrow, chamomile and goldenrod. " To attract beneficial insects and pollinators, consider yarrow , Roman chamomile, evening primrose and goldenrod" Rodale's Ultimate Encyclopedia of Organic Gardening
Garlic is sometimes suggested as a companion plant for Strawberries, although it is true that garlic discourages Aphids and many other insects and accumulates natural fungicide it is not an ideal companion for Strawberries.
I tried it once and was disappointed in my Strawberry yield and the flavor seemed to be adversely effected, perhaps by the sulfur of the garlic. While this alone hardly qualifies as proof positive, I would advise against planting garlic and Strawberries together.
Rue discourages beetles that feed on Strawberry Plants
Basil discourages beetles, aphids and mites that feed on Strawberry Plants
Thyme planted and/or placed next to Strawberries is believed to increase Strawberry yields.
Sage planted with strawberries is thought to enhance their growth.
Other Fruits and Berries Strawberries can act as a living mulch to some bush, shrub and small fruits. Suppressing weeds and retaining moisture. Choose companions which require a lower pH to thrive. Blueberries are ideal, they need acidic soil. Planting both near evergreens or Pines works even better as the decomposing pine needles provide high acidic conditions.
Tansy, a fern-like flowering plant that produces bright yellow flowers, is a general insect repellent. It also increases Potassium levels in the soil and is beneficial to most other garden plants. Its leaves are toxic to people, pets and livestock.
Avoid Fennel which is allelopathic to most garden plants. It exudes compounds designed by nature to eliminate competing plants from its immediate area. Dill is one of the few garden crops that can be grown with it.
1."...borage won't work in the same way as heavy doses of fertilizer and pesticides, it does positively impact strawberry yield." Strawberry Plants & Borage - StrawberryPlants.org
2. Plants Attract Parasitic Wasps to Defend Themselves against Insect Pests by Releasing Hexenol
How caterpillar-damaged plants protect themselves by attracting parasitic wasps