Fly by night duathlon. The entire bike course is on the Watkins Glen international speedway.

American zofingen duathlon meets your definition of hilly.

Both are very well organized[/quote

I've never done AMZOF but I know a lot who have and read their Race Reports. That's not the kind of race I would characterize as high quality event production. It strikes me as a unique cult race that people do for very different reasons. By contrast, I have done THE Powerman Zofingen and can tell you there is no comparison. The original in Switzerland has professional competitors, stadium finish, a race mascot, balloon arch start, helicopter and moto press coverage, expo, two volunteers at every turn, hilly as fxxk, etc., etc. ... and did I mention it's in Switzerland! The OP should do both.