If you live in an older building and favor historical and/or aesthetic continuity, Portland and Seattle-based Rejuvenation Hardware is a terrific resource. Specializing in period-authentic lighting, hardware, and house parts for old homes, it's also a great place to delve for fittings and fixtures if you're looking to introduce some Deco character or Arts and Crafts ambiance into a contemporary space that feels too stark.
Rejuvenation Hardware's stores and its web site carry a dizzying array of period fixtures and hardware, covering many popular American interior styles of the last 115 years. Browsing through this site's eight broad collections of light fixtures, lighting accessories (like switch plates, Victorian filament bulbs and glass shades), and various hardware doodads like brass doorknobs can take awhile. This is a company that takes great pride in the quality of their products, and everything is well-documented and organized on their website. If you know what you're looking for or have even a few parameters (like a size limit) you can find what you need pretty quickly by browsing the collections via Styles, Types, Decades, Base Price, or Size. If you don't know what you're looking for, browsing the site for inspiration via room type or customer pics can be a lot of fun. (The site also includes a "Chance" option and a Wizard that will lead you to products based on your answers to a series of questions.)
The "Pistachio Kitchen" includes Rejuvenation Hardware's Baldwin chain pendant, Swing Arm Halfway, Double Push-Button Switchplates, Single Duplex Outlet Coverplates, and Mushroom Cabinet Knobs.
This modern dining area incorporates a solid brass louvered Skyport pendant from the Modern America collection and an Enterprise wall bracket.
The Classic Frosted Shallow Bowl Shade is periodless and unobtrusive, and softens harsh ceiling-mounted bulbs.
Be sure to check out the period medicine cabinets, which can be customized to your measurements and specifications and then finished off with the hardware of your favorite decade. Prices are fairly high but fairly reflect the costs of period exactitude: researching, reverse engineering, tooling, sourcing, manufacturing and finishing small-run (and sometimes hand-crafted) hardware.