First post here on the site, and I must say it's nice that something like this exists. I have a deep love of traveling, and I don't know many people around me who enjoy it like I do. I don't do it for the destination; I like it for the trip itself.
That said, I did Springfield, IL, to Sacramento, CA in December (27th-28th) and blitzed through it in two days. There were four of us, and aside from a one-time 4 hour stop in a motel to crash and get a real meal and refueling stops we did it nonstop. All told it took us about 40 hours. We took the southern route -- went down through Oklahoma -- and rode 40 to Southern California, at which point we headed north until Sacramento. It's probably my second-best memory, right behind my wedding/honeymoon (which is why I was traveling in the first place).
That said, I want to do it again. I'll be doing it with my wife this time, and it will just be the two of us, so we'll probably have to pace ourselves a little more. She's not as into the breakneck pace thing as I am, and we would probably get too exhausted anyway. Granted, when I did it in December, I literally did not sleep the entire time except for the four hour stop. I normally sleep well in the car but I was enjoying the trip too much.
I'm in the early stages of planning, but the biggest thing I'm wondering is what route I should take. I really enjoyed the southern route, but i would like to try taking 80 all the way as well. I know that there are other routes as well though, and I know most of you will know them better than I will. Suggestions?