I won't take the trip through Switzerland, as long as you don't nececcarily want to do that. First of all it's a big detour and you'll face mostly boring highways, speed limits and plenty speed cameras. And if they get you on picture it's gonna be expensive.
So, what I would suggest instead: Black Forest. You can take nearly any route there (especially the smaller roads) and you will face some fantastic driving pleasure there. Speed limits aren't as harsh, you are allowed to do 100kph instead of 80kph in Switzerland and if you go 120 in Germany, you'll pay 30 Euros (43 $).
If you do 100kph instead of 80kph in Switzerland you'll have to pay 273$ and above 20kph you'll get into serious trouble that could lead to thousands of dollars. Switzerland is very nice, but if you want to enjoy your 1M a little bit, give it a wide berth.
Here's a little route form Munich to the Nordschleife through black forest. You won't drive such a big detour and you'll just not take the highway and go on the windy roads. That would be my recommendation.
http://maps.google.de/maps?f=d&sourc...8,5.163574&z=8
But keep in mind: That trip takes twice the time than the direct way would (10h vs. 5h). I don't know if you want to drive 10h? 5h would be more than plenty for me. But this would be highway only!