Hawaii East-West is a good one, a bit easy though. I usually like to do Birchwood (PABV) or Merrill (PAMR) to Pitka (PAGA) via Rainy Pass (stay in the actual pass just to keep it fun, just follow the lowest route on your map past the airstrip), or perhaps get the Glacier Bay scenery and fly around anywhere in Southeast AK. Theres plenty to see there.
If You're into big jets, though, you could try Stevens Anchorage Intl. (PANC) to Nome (PAOM), Fairbanks (PAFA), or King Salmon (PAKN).
Also, though it does take a full two days to complete, you can circumnavigate Alaska from Juneau using only VOR and NDBs (I never pulled up the GPS through the entire flight) in less than two hour hops using piston aircraft (under 180 knots) the whole way. For someone who doesn't know the proper and realistic stops, though, it would probably take a bit of research. It is definitely the most fun trip I have ever done, though. (its a shame that the Great Kobuk Sand Dunes aren't modeled in the game. Definitely one of the least known wonders of the world, also very fun to play in

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P.S. A tip for if you choose a route that reaches above the Arctic Circle. Do it at night. Perhaps there will be some Aurora Borealis

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