The Outlander series by Diana Gabaldon is not quite romance.  Not HEA.  But historically, it is wonderful.  Real sense of the time period.  Folks either seem to hate them or love them.  And carrying the books around is serious exercise.

I look at All About Romance's lists for suggestions.  (Lists are made by reader's suggestions.)  They have just updated their Scottish / Irish page.

http://www.likesbooks.com/scotsirish.html

I like Karen Ranney's Scottish books for light and interesting romances. 

I really like Nora Robert's Born in Trilogy.  Deals with an Irish family in Ireland.  Born in Fire, Born in Ice, and Born in Shame.  They are really good.

If you like contemporaries try Donna Kauffmann. She's fond of using Scottish heroes.

And of course there's Hannah Howell. 

Marsha Canham's The Pride Of Lions and Blood Of Roses are the best I've read and I've read many.  I'm still looking for good highlander romances, and this is one area where I consistently feel let down.  Some of Karen Ranney's books that are set in Scotland are good.  The Highland Lords series is mostly decent, but not fabulous, keeper level stuff.  A Scotsman in Love and The Devil Wears Tartan are very good, about A- reads; some minor flaws, but better than most other books like them.

Two on my keeper shelf ae Kimberly Cates' Gather The Stars and Theresa (Teresa?) Medeiros' Heather And Velvet., both Scotland.

The Cates book has a spin-off but it's set in London and it's also excellent. Trying to think of others but am coming up blank at the moment. There are still a lot of authors I haven't read yet - such as Marsha Canham - so have a lot of discovering to do myself.

I really like Allie Mackay (aka Sue-Ellen Welfonder). They are light reads and quite funny.

The reason I took up reading at age 48 is from reading Karen Marie Moning Highlander series. I just love that people can come up with great time travel stuff and for a little while, I actually believe it.

The other day I jokingly offered one of my books to my husband and he said he wasn't interested in anything I read because they always had a naked bagpipe player in them.

My other favorite is Kresley Cole and since you loved them too, you will probably enjoy Moning. I loved Outlander and couldn't put it down. I started with Hannah Howell's Highland Knight which was pretty good.

Susan King

Brenda Joyce - Dark Seduction

Diana Gabaldon, whom I LOVE.  Hannah Howell, Karen Marie Moning, Sue Ellen Welfonder, Teresa Medeiros, Donna Fletcher, Monica McCarty, Sophia James, Terri Brisbin, Veronica Wolff, Elaine Coffman, Janet Chapman, Lyn Stone, Amanda Scott, Sandy Blair, Lynn Kurland, Kinley McGregor, Arnette Lamb.

Diana Gabaldon hands down!  Also, some of Karen Marie Moning's scottish time travel novels are good.  I particularly enjoyed the Dark Highlander.