…because, as anyone who’s driven from Vegas to San Francisco can tell you, everything along I-5 is nothing short of utter fabulousness.
I’ll go with everything else and say Reno/Tahoe or Sacto. I dunno exactly where Shasta or Ashland are beyond a vague notion, but I could probably make those, too.
Sac has easy airport access, unlike many of the other options listed previously.
IF it is not to rude to ask, what vague part of Sac are you in? I’m in South Sac so you know I must be rolling in the money!
The south part of Midtown. Apartment dweller.
Maybe someday we can hope to find a house in the Fab 40s.
My votes
Sacto
Shasta
Ashland
My votes:
Reno - because it’s a ton of fun and I know the way
Sacramento - also because I know the way
Ashland - quite a long way to drive for me. Are there commuter flights reasonably priced there?
Wherever it ends up, it looks like I’ll be headed north and most likely driving, so if someone wants to carpool, I’m up for that.
Are you inviting me to cohabitate with you? You seem nice and all but I just don’t know you that well. But then again ig you could afford a place in the Fab 40s then I could get to know you awful fast.
The Garlic Festival is hardly boring, but I can hang with a Dopefest in Sacramento or Reno. I’ve got relatives in the area, and the wife and I want to hit some places in Reno anyway! 
As anyone who’s driven I-5 from Tj to Vancouver can tell you, the section you’re talking about is the low point of the I-5 corridor.
Hey, there’s an idea, how about Vancouver!
Now there is an idea. There would be some good and bad things about a dopefest in BC. Here they are as best as I can list them
Good:
One of the all time great cities.
Tons of stuff to do
Lots of hotels.
Beautiful location
Bad:
For us US dopers it is another country, and if we choose to fly we will require a passport to board.
Exchange rate not as favoable as it used to be
I would be all over a dopefest in BC. Say the word and I am there.
My votes are:
Ashland - (because it’s close and I’m cheap and lazy)
Sacramento - (because Master Control wants to go there so bad)
and
Ashland - (because I’m really cheap and lazy. Selfish, too)
Which Vancouver?
BC BC Vancouver WA is just a suburb of Portland.
Gotcha. I would so be up for a Vancouver dopefest.
Ashland sounds good. Though I must say June/July is around the time I’ll be moving so the chance I can make it is slim. It all depends on whats going on.
I’d say 50/50 I can make Ashland. Anything farther south would be out.
While I’d be totally down with a Vancouver 'fest if the time was right, it doesn’t really work with the whole “being as accessible to Left Coast people as possible” thing. Well, unless you meant, say, people between Anchorage and Cabo. 
Yeah because you know, let’s move it ENTIRELY away from a more central location to one of the extreme ends. You might as well suggest San Diego too.
Monterey can be either sunny and pleasant around the time we’re speaking of, or foggy and dreary. Not the best season to have a fest. Plus in summer ALL Of the tourists come here, so hotels are harder to come by and more expensive. Otherwise i’d be all for it, since I’m 7 miles north of Monterey.
My top three would be:
Tahoe
Shasta
Sacramento
Midpoint of the Left Coast? How about between the Aleutians and Tierra del Fuego? j/k
If using the I-5 corridor , Shasta Lake (about 15 miles north of Redding, CA), is the midpoint for the left coast of CA, OR, and WA.
Reno has a very efficient airport as well as Sacramento and the drive to Reno is very nice on US-395 and on I-80 as well. I love driving on the east side of the Sierras!
For me:
Reno
Tahoe
Sacramento
I am echoing Yeticus Rex 's list. Those are the top three for me. And probably the only three I could conceivingly get to.