Travel from Vancouver CA to San Franciso

the train prices can be the same as the bus. look at www.amtrak.com or www.viarail.com

There really is no "best" way to travel that route. The best one is the one that is best for you, considering your budget, time available, travel interests, and tolerance for fatigue.

Flying is fastest and may be comparable to train or bus. Renting a car gives you the most flexibility and allows you to explore places that are not served by bus or train. If you want to travel all the way down the coast, this is your only option unless you get really creative with a combination of Greyhound, local buses and finding rides with other drivers. Bus will probably be cheapest, but will also be the worst in terms of scenery and creature comfort.

You should look at getting to Seattle and organizing transport from here, as well as organizing transport directly from Vancouver. Greyhound takes about 24 hours from Seattle and costs $78 one way with advance purchase. AMTRAK also takes about 24 hours from Seattle. Or, rather, by the schedule it takes 24 hours. The Coast Starlight is notorious for being seriously late--as much as 12 hours has been reported lately, although AMTRAK admits only to 2-4 hours on the web site. Cost is $84.00 one way, but you might be eligible for a discount. With advance purchase, I found airfare for Seattle to Oakland for $88-90. including tax. Oakland is on the other side of the bay from SF and you can get to SF easily by transit

Awesome, thanks for all the feedback people. Much appreciated. Gives me something to work with.

Cheers

AT

Or since you didn't mention a time constraint you could take the train to Seattle (a picturesque ride along the coast) and then fly on down to SF.
That way you get the experience without possibly spending too long on a train.