One of the addictions of gardening is to plant things that really belong in other climates. This is otherwise known as 'Zone Denial'. With that said, many tropical plants will perform just fine in the cool Pacific Northwest when planted in the right location and given the proper care. For example, Windmill Palms, Succulents, Bananas, Yuccas, Bougainvilleas, Phormiums and more.
In many cases, hardy outdoor tropicals will survive our temperatures, but often succumb to excessive standing water. Ensure good drainage and protect from cold winds and your tropicals will usually survive a typical west coast winter.