The United States and South Korea both lifted their HIV entry restrictions this month. Two down, 57 to go, says UNAIDS:
"Some 57 countries, territories and areas have some form of HIV-specific restriction on entry, stay and residence that is based on HIV status. These include those that completely ban entry of HIV positive people for any reason or length of stay; and/or are applied to visa applications for very short stays (eg tourist visas); and/or are applied to visa applications for longer stays (visas for residency, immigration, asylum or resettlement, study, international employment, and consular service). Such restrictions, strongly opposed by UNAIDS, are discriminatory and do not protect public health."
Check out unaids.org for an interactive map of the restrictions: