What is the purpose of your drive from Reno to Crescent City?
Just to get there as fast as possible or maybe enjoy the drive (scenery) along the way. Do you enjoy good state highway blacktop or are you more comfortable sticking to Interstates?
All the three routes mentioned above have pros and cons to consider. Here is my take,keep in mind I have traveled all of these roads for many years.
Interstate 80 from Reno west has nice scenery, very rough surfaces, very heavy truck and RV traffic. If you take 20 at Emigrant Gap it has curves and can have heavy traffic. Highway 20 from west of Grass Valley to Calpella (at US 101) in my opinion is devoid of scenery and a pretty boring drive except along Clear Lake. Traffic along the resort towns of Clear Lake can be a real bear on summer days especially weekends. 101 north from Calpella is great Redwood forest/ park and ocean scenery country all the way to Cresent City.
Highway 395 Reno to Susanville runs through the high desert country and is a good 2 lane and 4 lane highway. Leaving Susanville there is a good stiff climb to get up on the bench but no real problem. Just west of Susanville turn north on Hwy 44 and on to Redding. Hwy 44 is a very good 2 lane state highway and presents no problems towing. The scenery in the north Sierra range and the south Cascades is worth the drive. Very good rest stop about halfway across at Bogart and don't pass up the scenic overlook stop to see Mt Lassen.
It's gonna be HOT in Redding so be ready. Highway 299 west of Redding to Arcata is a beautiful drive on good 2 lane state highway. Yes there is construction going on but most of the delays are now pretty minimal, but construction delays are everywhere in the west this time of year. If you can stop at a little roadside cafe called the Straw House in the small river community of Big Bar. The food is excellent and enjoying the river flowing past the patio is a great way to relax for a little while. Great Redwood parks between Arcata and Cresent City.
The last route taking I5 north from Redding to Grants Pass,OR takes you through some great mountain and river canyon scenery but the truck traffic can be bad sometimes. There is a serious traffic delay at the Antlers Bridge project can sometimes amount to hours depending on the traffic. Highway 199 from Grants Pass down to Crescent City is a good state highway passing through some great scenery. Be sure to visit the Oregon Caves, a must see in my opinion.
Hope this helps, they are all good roads, just depends on what you want or are interested in seeing.
Tinbender