Jadeveon Clowney, Defensive end

The last, and potentially best possible free agent the Browns should add is defensive end Jadeveon Clowney. Clowney was drafted first overall in the 2014 NFL draft. He has been to the Pro Bowl three times in his young career.
Clowney has underachieved according to some due to his extremely high expectations coming into the league. Despite not living up to the hype yet, he is still an incredible athlete and force on the defensive line. His pure talent and athleticism are hard to match in the league. He and Garrett would surely be the best pair of defensive ends in the league.
This addition would largely mirror the benefits of Griffen, but magnified more due to the talent Clowney is. Clowney is also only 27-years-old and heading into his prime. He can blossom as a part of the Cleveland defense.
His asking price has lowered significantly in the last few weeks. What was once over $20 million a year, has since dropped to around $15-17 million a year. The Browns can afford to give him a one-year deal easily.
As mentioned earlier, the Browns could cut Vernon for no dead money and replace his $15.5 million salary with Clowney and have a huge increase in production, or they could even keep Vernon for one more year and have one of the deepest and most talented lines in the league.
If the Browns could somehow add Clowney, the team would instantly get a lot better.
Any of the players on this list would greatly help the team in areas of need. Some proven veterans could be exactly what this young team needs as it looks to make a playoff push.