LWN
My employer just got a corporate subscription to Linux Weekly News, and it's a Good Thing TM.
I never really appreciated LWN until now, but it's something of an institution for those the rely upon Linux on a day-to-day basis. It's deep coverage of all things Linux blows discussion sites like Slashdot right out of the water, so if you like or use Linux on a regular basis, I highly recommend either getting a personal subscription to LWN or pestering your employer to get a corporate subscription. Keeping something like LWN around is good for everyone, and every little bit helps.