Sac...no doubt about it. Anything Bay Area (San Francisco, Oakland, San Jose, etc) is a traffic nightmare! Sac can have its moments, but not insane. Where in Reno/Tahoe are you headed. South Lake you want to take Hwy 50 to, Reno and North Lake (Truckee, Tahoe City) take Hwy 80. Have you considered flying into Reno...beyond easy. Depending on where you are heading it will probably be worth the little extra you might play to fly there. Alot closer to Tahoe.
I'm from Reno area by the way and lived in Tahoe for EVER. Graduated high school, married, and had my two kids up there. Any questions let me know!