Assuming June I'd skip Death Valley. But if you start from Las Vegas it is a reasonable detour (I'd still skip it myself. HOT doesn't even come close).

W/o DV, the most logical route would be San Diego, LA, up the coast thru Santa Barbara and up to Carmel/Monterey, cut across to Sequoia, > Yosemite, up to Lake Tahoe, over to SF and then up the coast through Mendocino and the Redwoods.

Or - you could drive up the coast as far as Morro Bay/Cambria then over to Sequoia, to Yosemite back to the coast at Monterey For this you'll want to back track a bit from Monterey/Carmel to see Big Sur and probably skip Tahoe.

For either - I'd want about 3 weeks . . .

Sounds like a plan to me. YOu might want to check out Lassen Volcano in CA too. In Between Lassen and The Redwoods is an awesome waterfall(almost as good as those in Yosemite) called Burney Falls. Myabe see Channel Islands Too.

Buy a National Park Pass on your first stop and save some $$

I think you need at least 2 nights between LA and SF, Monterey is too far to drive in just one day (3 nights would be better). I would stay in Santa Barbara, Cambria (or maybe Pismo Beach) and Carmel or Monterey. Pacific Grove would also be a good choice.
There are plenty of redwoods along the coast without having to drive to Redwoods National Park, but if you are driving to Oregon anyway, might as well see it. Have a good trip.

Yeah starting to have second thoughts about Death Valley

Thanks for the tip on Lassen i need to do some reading up on it.

I had the Channel islands on a previous trip itinery and it completely slipped my mind. Do you have any tips on visting the island (s). A favourite island/experiance. I know it gets increasingly difficult to reach the further out you go.

If the Tioga pass is open mid Juneish i can take that and explore the eastern Sierras a bit then push north to Lake Tahoe.

Is there anywhere else you guys reccomend. I was thinking palm springs just to veg out but i am not so sure.

Is there a reason you want to end in Oregon?
Are you flying to Las Vegas (or Phoenix) and renting a car?
My thought would be to leave LV and get to Yosemite by sunset.
Leaving Yosemite, head up I-5 through Sacramento. Visit Lassen if you want to. Get back on I-5 to Grants Pass Oregon and then take US 199 through Redwood to hit US 101 in Crescent City CA.
Head south on US 101 along the coastal route. I like traveling south along the coast so that there are no left turns across traffic to see the viewpoints. End in San Diego and return the rental car in Las Vegas if you have to.
The six month plan to see the US sounds great but you will probably drive several rental cars since most places don't like to rent a car for more than 30 days.

You have to understand our tomf . . . some time in a past life he must have been traumatized by a rental car drop off fee

He tells everyone to circle back to drop off the car where they picked it up. That might makes sense - might not. Depends on what car arrangements you've made and what the rest of your itinerary is like.

I live in N. California and frequently drive the coast - it honestly makes about this much difference { } whether one drives north or south. There are advantages and disadvantages to each. It is a narrow, 2-lane highway and it isn't like you have to cross 4 lanes of traffic to get to a turnout

I will have my own car from Canada (Montreal resident) so no drop of fees!

We are pushing into Oregan and Washington cause this is an America wide trip

We will be approaching from the South West so unless i do a mega loop i will be heading North.

I have heard comng south is better for hway 1 but as we are finding on this trip we cant do everything pefectly no matter how hard we try to fit it.

You have received some good advice and the rest is up to you. From LV - I would recommend driving over to here - SD - 5 hours - and hanging out and then head up to Anaheim (an hour or so) - if you want to see visit Disneyland - and then LA is another hour - and then head up the coast - stopping in Cambria (say 4 hours from LA if going straight through - but you might want to have lunch in the Danish themed town of Solvang - above Santa Barbara) - and also visit Hearst Castle. http://www.hearstcastle.org/

And if you are in a van - there are also some nice coastal campgrounds as you head up the Cal Coast.

From Cambria/Hearst Castle - the drive through Big Sur is beautiful - and spending a night in the Carmel/Monterrey area is a good stop - visiting Cannery Row, the Monterrey Aquarium and taking the 17 mile drive.

From there - you could drive over to Yosemite - and then to Lake Tahoe (assuming Tioga pass is open) and back down to SF - or go to SF from Carmel and then to Yo and to Lake Tahoe - and the "back way" up to Oregon - from Reno - past Lassen etc.

Or - from Tahoe - come back down 80 and head up I-5 to Redding, and on into the cute college town of Ashland - for an Oregon intro - and see nearby Crater Lake.

Don't think there is really a "wrong" way - just what you want to see and do.

For Oregon and Washington - there also plenty of other posts in here.

I just did a California road trip last summer from LA up to Oregon and back. Trying to figure out how to integrate Yosemite, Sequoia, Death Valley and the Pacific Coast Highway (PCH) was the hardest part of planning the entire trip - and we were not successful. We had to drop Sequoia/Kings Canyon. Mind you, this road trip was 40 days.

The main problem is that one needs two to three swings up and down the state to visit the spots mentioned above, and the mountains make it impractical, sometime impossible (or impassable as the case may be), to travel laterally across the state to do it.

If you're coming from Las Vegas, I'd say go through Death Valley, the Eastern Sierras, hook upwards to Mono Lake/Bodie and through Yosemite and then Sequoia/Kings Canyon as part of your way down to Southern California. Then from there you can take the Pacific Coast Highway as a straight shot up through SF, Mendocino, Redwoods and onto Oregon. You're next dilemma then is if you want to see Lassen/Burney/Lava Beds which are on the eastern side of the state.

I kept up a blog of my California road trip if you want to see more details, maps and photos. It's at: http://calroadtrip2012.blogspot.com/