Stairway did not make my cut. I do think they kinda "borrowed" a bit too much for that song, so it's kind of on principle.
Odd criteria, all things considered. At least with Dazed and Confused, Whole lot of Love and Babe I'd Gonna Leave You - the band were successfully sued, and have since changed song-writing credits.
The truth of their songwriting controversies is a little more nuanced than this. To wit:
Dazed And Confused - Jake Holmes dropped his lawsuit in exchange for a shout-out in the liner notes ("Inspired by Jake Holmes"), but the actual songwriting credit was not changed.
Whole Lotta Love - Willie Dixon dropped his lawsuit in exchange for a lump sum and a 1/5th writing credit.
Babe I'm Gonna Leave You - Anne Bredon didn't file a lawsuit. She just had her publisher contact Zep and they subsequently adjusted the writing credit.
I'd also argue that on an ethical level, Zep's actions were 100% justified in the case of BIGLY (since Joan Baez had improperly claimed that it was a traditional song). I also think that Zep got a bit of a bad rap for WLL, considering the fact that it was an acceptable practice in the '60s to take credit for re-written blues songs. Willie Dixon himself was no stranger to the practice.