Couple of different styles here. Both are accomplished guitarists, and probably more talented as writers and composers. This is a tough one for me, because I think Bruce's best slays anything Lindsey did, but he also had some really off moments. Both have also stood the test of time, still touring and performing admirably to this day even into their 60s. I didn't know this until just now, but they are only 10 days apart in age from each other. Both are in the RnR HoF (LB in '98; Bruce in '99), and have a few other similar awards/acknowledgements of their talents.
This is a tough one. But, he is called "The Boss" for a reason.