I started with the tiny Rivoli chair tool, way back in college. Always worked well but eventually got lost between moves and the long stints of not working on bikes as other interests came up through the years. A couple of cheaply, no-name chain tools were passed on to me in the last ten or so years, but eventually I decided to get a proper quality chain tool in the form of the Park CT-5 mini chain tool. Not quite shop grade, but has worked flawlessly since I got it some six or seven years ago. I don't think it will ever break on me, so I'll never have an excuse to get anything else......