I'm just going to rank Still, Worthy and Reyes because we presumably have no shot at Cox, Brockers and Poe.
1.) Still- By far the most productive of the three (55 tackles, 17.5 for loss), with very good length (6'5) to get in the passing lanes He's also very disruptive in the opponents backfield shooting the gaps with a quick burst off the snap.
2.) Worthy- His production doesn't show it, but Worthy also has a great burst off the snap enabling him to either shoot the gap or bull rush his man in to the backfield. Has a very wide build and low center of gravity giving him the ability to hold his position at the point of attack while facing double teams making him an optimal run stuffer and because of that I think he would be the best fit for the Giants. Him and Joseph would be an excellent combination as 2-down run stoppers.
3.) Reyes- Despite great combine numbers, I don't see the same type of quick burst off the line as the other two possess therefore getting him stone walled at the line of scrimmage far too often. IMO not worthy of a 1st round pick and personally I wouldn't even consider him till the 3rd.