If you're specifically looking for snow this year then Lassen will be your most reliable go, followed by Shasta. I have no idea how much snow sits beyond the Mammoth webcams, although earlier in the season it was -zero-. But Mammoth is your best bet down close.
Also: Unless you actually SEE snow on the front side of the Sierras, don't bet on it. It's been a very funny year for wet-side snowpacks, and some of the biggest wet-snow areas are suffering the most. Take a look at Ashland, for example. Normally swimming in snow, they've had two years in a row where they couldn't fully open the mountain. (Wanna buy a ski area?)
