NFL teams aspire to build through the draft and supplement with veteran acquisitions. But sometimes those veteran newcomers become much more than "supplemental" contributors. In best-case scenarios, they become key components for contending teams, upgrading positions that otherwise might have been liabilities. We're deep enough into the 2014 season to identify the best veteran acquisitions via free agency and trades. I've taken into account performance and value in putting together a top 10. Teams that were already successful appear better positioned to get value from the veterans they add. Receiver Golden Tate is the only player on the list from a team that had a losing record last season, but he is not in the top slot.