How about the Canadian Regional? It's the only one in another country but it's full of competitive teams like 48, 188, 783, 639...
This year, the 70+ teams, 2+ fields, and up to double the qualifying rounds should make it one great regional. I don't know if anyone can judge a regional's competitiveness with clear objectivity but I at least know that the Canadian Regional willl be highly entertaining and fun. As it has been the last 2 years.