My all-time favorite fixture purchase was a simple vintage nickel towel bar I installed in my Seattle bathroom (I wish I had unscrewed it and taken it with me when we moved). If you're after a similar vintage look in your bath, consider searching for old fittings at one of the many online architectural salvage yards; Hewn and Hammered has a great listing of online resources. (For those in pursuit of new fixtures, see 10 Easy Pieces: Towel Bars.)
Below is a sampling of three selections from Historic House Parts:
Glass towel bars with nickel fittings from Historic House Parts.
Clear glass towel bar with porcelain fittings from Historic House Parts.
Belgian enamel towel bar from Historic House Parts.
Vintage Chrome Towel Bar at Nor'East Architectural Salvage.
Glass Towel Bar, also at Nor'East Architectural Salvage
Assortment of towel bars from Pasadena Architectural Salvage.