I'm with you on the Central America and Ethiopia coffees. Those seem to work the best for me. Just finished a 10 lb. lot of Ethiopia a few weeks ago, it was one of my favorites.
Always had good luck with Guatemalan, too.
Just started into some El Salvador, first time. These beans go through development phase real fast--didn't expect that. I usually go about 20% development time, but with these it ended up well into med roast at 20%, farther than I wanted to go. A bit too roasty. Will back off to maybe 16-18% next batch.