wrote
I'm looking for challenging instrument approaches in the United States
that I can have my students fly on the simulator.

I'd be interested in hearing your suggestions. Any type of IAP is
welcome as long as it makes the pilot work a little bit.

If your simulator supports circling, try the NDB-F at EYQ. Configure
the winds to strongly favor rwy 9, set the vis to the minimum 1 mile,
and note the circling restriction. Fun.

Michael