Do you keep spotting pieces or design elements time and again over a period of years that you never tire of?  For me, at times I go through stages with certain "looks" or trends that I may find interesting for a time and then get sick of after they have saturated the market and every magazine, blog and retail outlet.  
The more "seasoned" I become with increased exposure to design, there are certain timeless icons that I find perennially appealing. Take for instance this Saarinen tulip table from Interior Addict. My brother had one of these in his Manhattan apartment 10 years ago. I liked it then and I still like it now.  It's timeless American mid-century design at its best; the white goes with everything, there's no awkward "legs" for anyone to navigate and the oval marble top is simply beautiful. This classic is just as appealing in a hyper-contemporary loft as in a charming traditional bungalow mixed with antiques. Find this classic and more at Interior Addict
I'd love to hear what would make your list of tried and true design favorites. Do tell!!