Kim Gordon, Thurston Moore and Lee Ranaldo all had tracks they were main vocals on. Majority were Kim/Thruston maybe about equally unless someone with more knowledge wants to correct me. Some songs fronted by Thurston might be worth digging into to see if Paul is more of a fan. Silver Rocket might be worth checking out. The mainstream pick from the same album would be Teenage Riot, that song along with Kool Thing here got a lot of SY's radio play. Eric's Trip is also a good song sang by Lee. Couple songs from earlier album (Sister) would be decent choices as well. Maybe Catholic Block and/or Schizophrenia. SY has a very long 20 year long set of albums. While even to the end they still sounded uniquely "Sonic Youth" I feel like their songs can get a widely different reaction from people as they often skirted with more mainstream sounds to more abstract noise rock. I tend to prefer the later but it's definitely an acquired taste I think. Tim hit his early comment on the head. Sonic Youth feels like a lot of popular bands "favorite band" or were influential to a lot of groups that came after and found more mainstream success.