Quentin Nelson- I'm a big "position value" guy, but assuming Barkley and Chubb are gone, this is a can't miss prospect at one of the 2 biggest needs for the Bears. If you like BPA, there's no chance he's not the best player on the board if he's there at 8, unless Barkley beats up his girlfriend this week, while smoking a bong on his knees during the national anthem.
Tremaine Edmunds- Another anti position value player. I think it's overblown how raw Edmunds is and understated how good he currently is at ILB, especially in coverage. Also plays a need position. A unique athlete. If the Bears miss out on Nelson, there will be other good guards that may even be better fits in the zone blocking scheme. Bears miss out on Chubb, there are other pass rushers who could get after the QB. There isn't another 6'5", 250lb LB with Edmunds' skill set (sorry, not a Vander Esch fan, and he'll be gone by 39 anyway). Throw in even a little potential on the edge, and he'd be tough to pass up.
Roquan Smith- Again, position value not there in the top 10. But he's a guy you can build a defense around ala Patrick Willis. There's no projection with him. What you see is what you're going to get. And what you get is a leader, who can fly around the field and be a tackling machine. Safer pick than Edmunds, though more limited upside. While Edmunds has a slight shot to help on the edge, and Nelson has a slight shot to be a tackle because he's so good, Smith is only going to help out in 1 area. But he will be very good in that area.
I'm pretty intrigued by Derwin James, who'd be my 4th. There's some that think he can play some corner. We know he can play in the box. He can play FS. With as much as the Bears play nickel, Fangio could move around James, Amos and Jackson between deep middle, slot, and rover. The back end of the D would be fast and versatile. James may have the most upside of any defensive player in this draft. If Fangio can figure out how to maximize him while not lessening Amos or Jackson's role, then the Bears could have a potential stud.