What a fascinating thread! Thanks for starting it, Lantana.
My own background is German, but while I love the dirndl, it doesn't love me back--my wide shoulders, small bust, rectangular waist just don't work it, and the tiny florals don't suit my large features. (I had to replace an airline-lost wardrobe in Germany at age 12, and NOTHING was the right shape for me!)
My husband is of Scots heritage, my 3 daughters have all been Highland dancers, and as a teen I hung out with friends who did the same. It seems that attire is more up my alley. The kilt is traditionally the man's garment, but it appeals to my classic/preppy instincts (though I wouldn't wear it with the velvet jacket and fur sporran!) The traditional ladies'wear consists of a plaidie or huge tartan scarf, worn draped from one shoulder, over a long (white) dress or a full-skirted outfit, and sometimes I riff off that too (with a black dress) for formalish wear. Of course I love anything tartan, and one day I WILL own a full, floorlength taffeta skirt in the Black Watch.
I love Indian traditional dress as well--I even have a sari (which I've only worn on one occasion, but I do know how to wrap it). Again, my shape suits other things. I brought home a salwar kameej from a med school elective in Nepal, but sadly outgrew it after having kids. But I love the silhouette (Chanel 2012 was so inspiring but went nowhere) and sometimes I'll echo it with a straight dress over leggings (kneelength, or longer with side slits).