Mariah Carey’s ‘We Belong Together’ was No. 1 on the Billboard Hot 100 for an eighth week Wednesday and also ruled the Pop 100 and Hot R&B Hip-Hop charts. Rihanna’s ‘Pon de Replay’, moved up to No. 2 on Hot 100 and advanced to No. 5 on the Pop 100, with Gwen Stefani’s ‘Hollaback Girl’ holding its spot at No. 3.