I agree we all tend to have preferences to what we know are wonderful rides in our area and, your best bet is to either get a book or, use an online motorcycle touring site (here
is a link for some good ones) for specific recommendations on routes, sites, amenities, etc. There are an unlimited number of ways you can get from east to west. Going through the many areas of the Rocky Mountains, while unusual, you can run into snow any month of the year. If you go to Death Valley, expect temps WELL over 100F. Even areas beyond Death Valley can be extremely hot. Two summers ago, my wife and I ran into a stretch between Zion National Park (southwest Utah) and Las Vegas of 116F. I recommend you pack a cooling vest for that part of the trip. We would have been in trouble without them.
Still, I have some personal recommendations. If you like to scuba dive or snorkel, there are a number of crystal clear springs throughout central and north Florida, with many located at state parks (camping). From Atlanta consider going to up to and riding Tail of the Dragon in east Tennessee. Jaunt from there to Natches Trace Parkway (pick up it up just south of Nashville). It cuts southwest and gets you fairly close to New Orleans. I've got no particular recommendation to Fort Worth (my home town, BTW) as I have not been riding in that area. However, once there you may be able to pick up a Texas Ranger game if you like baseball, can experience Billy Bob's (world famous western nightclub), etc. Your friends should have some good ideas. I presume you will do Hwy 287 to Amarillo. Picking up the ride at Santa Fe, go up to Pagosa Springs and on to Durango and then Mesa Verde National Park. Nice camping there and, the cliff dwellings are a must-see. If you happen to stay in Durango and, the next day day have a half a day to spare, you can take the Durango-Silverton train to Silverton and return by bus to get you back to Durango by 1:20. Anyway, take Hwy 160 through Mexican Hat and on to Hwy 89, taking that south to pick up 60 for a drive along the sough rim of the Grand Canyon, splitting off onto 180 into Flagstaff. Beyond that, the Sequoia Redwoods are awesome, as is the trip up the coastal highway. If you make it that far up the coast, the Hearst Castle is quite the site to see, if you have time to take one of the tours.
There is so much to see, your major task will be to avoid boring routes where you could just as easily have taken something breathtaking. Know that there's not much you can do about west Texas, though. I know the southern part of our Travel Stops map is not well populated but, you may see if there is anyone along your route that can offer some hospitality. You may also want to seek out hostels which, give the opportunity to meet interesting folks.