It would be nice compiling a list. I asked the same question a few months ago, and answers I got were:
USAT Nationals
Herballife LA Triathlon
Legacy Tri Long Beach
Lifetime series (NY and Chicago) although NY didn't seem too competitive outside of the pro field.
St. Anthonys
I'd add the state champ races tend to be pretty competitive usually.
Would be nice if they brought back some sort of competitive series.
Not sure why the Minneapolis lifetime tri got cancelled.
Professional interests in Genomics, Bioinformatics, Hardware/Software interfaces, sports interests are running from 800 to half marathon, sprint tri to half iron, cycling road races
https://brave.com/ - A safer and faster way to browse the web
https://www.strava.com/athletes/3757906
USAT Nationals
Herballife LA Triathlon
Legacy Tri Long Beach
Lifetime series (NY and Chicago) although NY didn't seem too competitive outside of the pro field.
St. Anthonys
I'd add the state champ races tend to be pretty competitive usually.
Would be nice if they brought back some sort of competitive series.
Not sure why the Minneapolis lifetime tri got cancelled.
Professional interests in Genomics, Bioinformatics, Hardware/Software interfaces, sports interests are running from 800 to half marathon, sprint tri to half iron, cycling road races
https://brave.com/ - A safer and faster way to browse the web
https://www.strava.com/athletes/3757906