In the early 90s Oiler owned the streets of LA with crazy permanent spots. He had tons of tags on the backs of street signs. I recently took pictures of some other graffiti artists' tags that have been around for many years. I love seeing tags that don't get buffed, because, well, they are super difficult to buff.
Atlas CBS LTS, Aloy TKO SKA 2003 - downtown Los Angeles
CBS - k9er, Joust, Spoke EI OTR - Mid 1990s - South Central Los Angeles
Pysa Zes MSK 2009 - Koreatown
Zes Ayer (RIP) MSK KOG - Los Angeles (near the huge UTI production)