Best airport for train to Murren/Lauterbrunnen/Wengen area?

Zurich for an overseas direct arrival. And Zurich or Basel/Mulhouse if you land somewhere in Europe first. Both 2.5-3 hours by train to Lauterbrunnen, Zurich maybe ten minutes faster on average.

3.5 hour train from Geneva. 5.5-6 hours train time from massive international hub Frankfurt, which is probably all totalled about a wash (or a little better) than connecting from there onto a flight to Zurich or Basel/Mulhouse.

Zurich for sure. It's super easy to hop on a train from the airport and head straight to that area. Then, most people like to spend their last night(s) in Lucerne and take the train right from there to the airport for their flight home.

I did a general flight scan, and quite surprised at how few direct flights there are between DC and Zurich! Like not every day I think? I would have thought that there would be many.

But connecting flights on TAP (Lisbon) and Icelandair (Reykjavik) are quite cheap and quite reasonable layover times.

Note that on SWISS (and probably other *A carriers) you can book a plane ticket all the way to Interlaken now. May be worth consideringe.

United has a daily flight between IAD and Zurich. I will be on it in 10 days (but who is counting?)

Zurich for sure. As @Hank mentions, TAP is cheap and I just found out they started a new stopover program that includes DC as a departure point. So if you want to add a few days in Portugal that could be an option! https://upgradedpoints.com/news/tap-air-portugal-stopover/

Thanks, all!! I haven't travelled in so long I hadn't even heard of TAP :D. Will definitely check it out. How budget is it???? I definitely will be checking a bag, and my husband probably, too!