I too just installed the Sylvania SilverStar bulbs, (low beam 9006 and high 9011). By the way, I have never had an easier time with access to the bulb area, just follow the instructions in the owners manual and the whole assembly pops out. I am really happy with the result, certainly an improvement over stock. Yes, pricey (more than $20 per at retail). But better than the blue spectrum bulbs out there for brightness - I tried those on another vehicle.
I also have some Hella Black Magic lights from my last rig that I am also going to install (they come on with the high beam circuit - I have 100 watt bulbs in them.) I am a fanatic about being able to see, on or off road, at night. Problem - not sure where to mount them since the idiots at Chevy did not include tabs for lights on the grill/brush guard.