I can only speak about the guys that I've seen play.
Since 2000:
1. Jason Witten
2. DeMarcus Ware
3. Tony Romo
4. Sean Lee (when healthy)
5. Terrell Owens
Honorable Mention: Larry Allen, Dez Bryant, Zack Martin, Travis Frederick, Terrence Newman
Well, I can argue with you cause I started watching NFL and following the boys since then too. Witten is a lock. Tony, well, maybe too. Ware was just too good to not pick him.
Now, Sean Lee? 2016 was his only one truly great. TO? C'mon, were talking best All time (in our case, since 2000). COWBOYS all time, he played for the birds, thats an instant out of list to me.
Now, if youre watching since 2000, you watched Emmitt, too. He cant be out of that list.
And LA was too good to leave out.
My list: (since 2000)
Witten, Romo, Ware, Emmitt, LA.
BUT, as I watched a lot of films and read bout our history and as much as I could, my list of cowboys ALL TIME would be:
1- Staubach.
2- Emmitt.
3- White.
4- Landry.
5- Witten.
Honorary Mention: Jimmy.