Bigdog has good advice.
I'm not a huge fan of Crater Lake. But the drive up the east side of the Cascades, from Klamath Falls / Medford area, is beautiful. So is hwy 199!
If you take hwy 58 from there towards the coast you can stop at Salt Creek falls. Other routes have waterfalls, too, but I like that one.
The road from Roseburg to the coast is a pretty one.
Somebody on the previous page said you should consider driving the coast on a southbound route rather than a northbound one. That's because it puts the views out your driver's-side window instead of the passenger side. But it's amazing, either way. Don't miss the bit between Florence and Bandon -- high cliffs and sea lions.