fly to Scandinavia best place to fly in and out of?

Well, if you want to minimize travel time, you are looking at flying into either Oslo or Helsinki, since those are on either side of your trip (unless you are zipping back and forth for some reason) if possible. United/Air Canada has an option that flys into OSL and out of HEL. You might look at that. You'll need a train or flight to ARN (Stockholm, and then you can take the boat overnight to HEL from ARN. Alternatively, just fly. That for the round trip (no intraScandinavian connections) is about $1,300 pp. Finnair has some cheaper flights into HEL and out of ARN (Stockholm). You would have to backtrack to ARN from OSL. Not that big of a deal, really, given the train and many planes that connect the cities. This runs you about $1,000pp. They also have a flight that will get to you ARN and return from HEL for $984, which is as cheap as I see it right now for my random dates. Go to kayak and do a multi-city search. That's where you can find your answers.

Agreed, you probably want to do an open jaw ticket, which is a round trip ticket but in/out of different cities. It doesn't make sense to get yourself back to your city of origin since they are all so far apart of one another. When checking itineraries/prices, use the "multi-city" option rather than one-way or roundtrip. SAS is another good airline to check.

I've seen good fares on FinAir into Helsinki. Take a overnight cruise back over to Stockholm and a train to Oslo and Bergen. Then fly home from Bergen after taking in all the fjords.

We flew into Copenhagen on SAS, because we could get a non-stop flight from Dulles. The flight is the worst part of my trip, so I always try to book non-stop to limit the suffering. It was a good choice. When you fly SAS they offer you great fares for Scandinavian hops (we didn't take advantage of it). I'm not sure if Helsinki is included, but you can always ferry from Stockholm.