Harvard, Yale, Princeton, and Stanford are the best known schools with REA / SCEA where the applicant is not supposed to apply ED anywhere and not supposed to apply EA to schools not falling under certain exemptions, However, “single choice” EA is sort of a misnomer, since the exemptions listed on the web sites are quite numerous (e.g. public schools, early deadlines for scholarships, rolling admissions, non-US schools).
Tulane used to have both SCEA and EA, with SCEA as an indicator of a higher level of applicant’s interest. Its SCEA was more restrictive, with fewer exemptions than at HYPS. Tulane now has ED instead of SCEA (and still has EA).
Georgetown has EA with only the restriction that the applicant not apply ED anywhere.