Boston->Pittsburgh (Interstates 90, 84, 81, 76)
Pittsburgh -> Denver via Kansas City (I-70)
Denver->Seattle (I-25 to I-90)
The reasoning behind this route was visiting friends in Pittsburgh and KC, and going through Denver because of stories I'd heard about a really awesome stretch of highway going up into the mountains there.
The problems are a) takes almost a full day longer than the direct route (I-90 the whole way); b) the Pittsburgh->KC stretch doesn't divide well into driving days, which means I either lose half a day or only stop in KC for lunch, which doesn't seem worth the detour. The appeal of Denver is also offset by the endless tedium of Kansas.
Problems with the northern route are that there aren't really any people I know that I can crash with (which means higher expenses and perhap more boredom), and I'm not really sure that South Dakota would be any better than Kansas. On the plus side, I go right by Mt Rushmore and Devil's Tower, should I feel the need for a brief diversion.
Then of course, there are miscellaneous hybrids of the two routes; stopping in Pittsburgh and then cutting back north to I-90 via the PA turnpike; cutting north to 90 from KC, which keeps the detour but eliminates Kansas. I'm trying to remain somewhat flexible with regards to how far I drive in a day - I've never driven more than 5 hours at a stretch alone before, let alone for five or six days straight. I'm hoping to manage at least 10 hours/day, but I really have no idea how feasible that's going to be.
It's tempting to just plan on taking my time, stopping and see people and landmarks, and I'll get there when I get there. I'm guessing, though, that after one or two days I'm going to just want to get there, screw the scenery. I have told my landlord to expect me by the 14th at the latest (though granted I could always get a message to him if I was going to be late - I've paid rent for this entire month, so it's not like the apartment's going to go away.)
Result: extreme ambivalence. I don't know how I'm going to react psychologically to this trip, and while I could play it by ear I'd like to give people warning if I'm going to show up on their doorstep demanding a bed :)
Anyone familiar with any portions of these routes care to offer opinions or suggestions?