Notice how Q2's dynamic lights seem to be the same brightness from center to edge? I think that sucks. Let's make them look better:

Open gl_light.c in the ref_gl project.

Go to R_AddDynamicLights.
Locate the lines:

pfBL[0] += ( frad - fdist ) * dl->color[0];

pfBL[1] += ( frad - fdist ) * dl->color[1];

pfBL[2] += ( frad - fdist ) * dl->color[2];

Change that to:

pfBL[0] += ( fminlight - fdist ) * dl->color[0];

pfBL[1] += ( fminlight - fdist ) * dl->color[1];

pfBL[2] += ( fminlight - fdist ) * dl->color[2];

yeah, that's really it. Dynamic lights are a bit harder to see now, but they sure as hell look better.
Much better. Have fun.