Personally, I'd go US 50, or hook up and travel via old route 66.

Check out the following book, it has a great list of cross-country trips
and hilites all the places to stop on the way:

ROAD TRIP USA: Cross-country adventures on America's two-lane highways.
By Jamie Jensen  ISBN: 1-56691-036-6
Published by Moon travel handbooks $22.50

I used this on a trip following route 66 from CA to KS this summer - it was
great!

At 10:52 PM 10/29/97 -0500, Sudhir Desai wrote:
>fellow listees,
>need your opinion on which route to take to CA
>
>
>here is the route i plan to take this summer to go to San Diego.
>there are 2 ways to go from Germantown, so i will list them according to
>preference(first is first).
>
>Catonsville, MD to Germantown, TN
>Catonsville, MD 95 south        0 miles
>Wash. D.C.      495 west        35 miles
>-- VA --        66 west
>Front Royal, VA Skyline Dr.     90 miles
>Waynesboro, VA Blue Ridge Pkwy. 199 miles
>-- NC --        BRPkwy.         412 miles
>Asheville, NC   40 west         552 miles
>-- TN --        40 west         598 miles
>Germantown, TN                  1025 miles
>
>
>Germantown, TN to San Diego via 50 and 1
>Germantown, TN  55 N/W          0 miles
>-- Arkansas --  55 north        8 miles
>-- Missouri --  55 north        83 miles
>St. Louis, MO   50 west         282 miles
>-- Kansas --    50/35 west      537 miles
>Emporia, KA     50 west
>-- Colorado --  50 west         1013 miles
>Grand Jnctn, CO 50/70 west      1458 miles
>-- Utah --      50/70 west      1483 miles
>Salina, UT      50 west         1668 miles
>Delta, UT       6/60 west
>-- Nevada --    6/60 west       1825 miles
>Ely, NV         50 west         1889 miles
>-- California --50 west         2236 miles
>Sacramento, CA  80 W/S          2343 miles
>SanFrancisco,CA 280 south       2439 miles
>Daly City, CA   1 south         2449 miles
>San Diego, CA ----------------- 2983 miles
>Germantown to San Diego ------- 4023 miles
>
>------------- OR -------------------------
>
>Germantown, TN to San Diego via 66/40
>Germantown, TN  40 west         0 miles
>-- Arkansas --  40 west         20 miles
>-- Oklahoma --  40 west         309 miles
>-- Texas --     40 west         644 miles
>-- N. Mexico -- 40 west         813 miles
>-- Arizona --   40 west         1189 miles
>-- California --40 west         1550 miles
>Barstow, CA     15 S/W          1707 miles
>San Diego --------------------- 1883 miles
>Germantown to San Diego ------- 2923 miles
>
>
>the difference in times/distances is that the route 50 and 1 way will take
>an extra day or 2 for sightseeing purpoises along HWY-1, and acclimating
>to the realization that if your tire pops along HWY-1 southbound, you're
>dead...
>
>
>please tell me which route would you take if you had the chance to take
>either route?
>
>
>thanks in advance,
>Sudhir H. Desai                         1984 VW Vanagon 3.4 liter Chevy V-6
>cdes@welchlink.welch.jhu.edu            1996 Subaru Outback 2.2 liter flat-4
>sudhir_desai@geocities.com              1997 Jeep Cherokee
>
>http://www.geocities.com/MotorCity/Speedway/1889
>
>