I can't pick just five, so I'm breaking mine into categories
TOP FIVE COUNTRIES
1. USA
2. Canada
3. Italy
4. Argentina
5. Iceland
TOP FIVE LARGE CITIES
1. San Francisco
2. Vancouver
3. Rome
4. Buenos Aires
5. Cairo
TOP FIVE SMALL CITIES/TOWNS
1. Innsbruck, Austria
2. Ushuaia, Argentina
3. Cesky Krumlov, Czech Republic
4. Bandon, Oregon, USA
5. Sucre, Bolivia
TOP FIVE NATIONAL PARKS
1. Yosemite (USA)
2. Olympic (USA)
3. Jasper (Canada)
4. Torres del Paine (Chile)
5. Glaciares (Argentina)
TOP FIVE MANMADE SIGHTS/RUINS (admittedly, haven't done a lot of this stuff)
1. Tikal (Guatemala)
2. Golden Gate Bridge (USA)
3. Abu Simbel (Egypt)
4. St. Mark's Square (Italy)
5. Indoor Skiing (Dubai)