The simple act of inviting a Buddha, Bodhisattva, Goddess, Deity, Immortal or a Saint in your home or workplace will shower upon you wonderful blessings of peace, luck and protection. Having a Sacred Image can immediately transform negative energy into positive ones, and if the energy is all positive, it can ensure that the energy stays positive.
Sun Wukong aka Monkey God aka Pilgrim aka ‘Great Sage, Equal to Heaven’ is a very powerful wealth and protector god. He is one of the few deities worshipped both in Taoism (also spelled as Daoism) and Buddhism.
Avalokitesvara or Kuan Yin is known as Cannon in Japan. Notice that even though the image looks feminine, the breast is exposed and its flat signifying a breast of a man. This is to signify that Kuan Yin has no gender.
Kuan Kong / Guan Gong / Guan Ti / Guan Yu / Guan Sheng Ti Jun
Constantly seeing the images of Buddhas, Bodhisattvas, Deities, Immortals, or Saints will also subconsciously connect us to higher form of consciousness.
While I prefer actual images of the Buddhas and Bodhisattvas, etc. Other sacred objects like Prayer Wheels, Stupas, or the Koran for Muslims or the Bible for Christians will also do.
A table top prayer wheel.
An indoor stupa is only effective if it either has a relic or a sutra or mantra inside it. A real relic is very rare though.