Lil' Wayne - Tha Block Is Hot
Xzibit - Year 2000 (Paparazzi/What U See Is What U Get weren't really mainstream hits)
Jay-Z - Can I Get A... (older singles like Ain't No Nigga and Always Be My Sunshine weren't big, but Jay-Z blew the fuck up after this song, plus it kind of helped launch Ja Rule's career)
Bone Thugs-N-Harmony - 1st of tha Month (Thuggish Ruggish Bone and Foe tha Love of $ were popular, but they weren't BIG yet)