A J.C. Higgins (Sears) Model 88 .22 revolver with 4" barrel and fixed sights. I bought it in 1956. I disliked the grip, so I built it up with wood putty and finished it off with friction tape. Fired almost exclusively single action over the decades. As a result, the double action could use some work. The finish could too.
Second candidate: a 9mm Browning Hi Power T-series bought in 1968 and carried as my personal weapon of two flying cruises during Vietnam. All gussied up now with a C&S SFS kit and Crimson Trace grips, I fire it weekly at my range -- only standard pressure. Then afterwards, as I clean it, I admire it.
Cordially, Jack