Japan

Japan is the safest country for solo travelers in the world — violent crime rates are 1/20th of the US, lost wallets are routinely returned with cash intact, and you can walk any street at 3am without concern. The rail system (Japan Rail Pass) is the world's most reliable, signage is increasingly in English, and convenience stores (konbini) provide restaurant-quality meals 24/7 for $3-5. Solo dining is culturally normal: ramen shops have solo counters, and ichiran ramen literally has dividers so you eat alone by design. The only downside: it's expensive ($80-120/day), but you get extraordinary value for it.