I guess I would have to say my favorite DL was Gathers. It was such a shame he got sick. He would own the sack record by a large margin if he stayed healthy.
Although the game may not have been as high profile as some of the others mentioned, the back to back sacks by MJ to finish the Maryland game were probably the most "game saving" as anythng I can remember. UM was first and goal inside the 5 after a huge play and the game hanging in the balance with essentially no time left should they have scored. It was do or die. The only game I can remember where a goal line stand made the difference was Clemson 1990, but that was not the end of the game I don't believe.
There have been a lot of good games played against us by a DL player, but it is hard to pick one over Vellano's effort a few years ago. 20 something tackles, right? How often do you see a DL player have 5 tackles in a game, let alone 20 something? Admittedly, you have to consider where on the field some of those tackles were made (many after substantial gains), but the sheer level of hustle indicated is amazing.