Best "Rock/Pop" Debut Album?

I've been thinking about this for a while and recently rifled through my catalogue to look at some contenders. The criteria I used for selecting the best debut album is based on both impact to the genre and overall musical quality. For example some of the great Rock/Pop bands of the last 45 years didn't exactly come out of the gate swinging grand slams. For example, as great as the Beatles, Stones and even The Who were or are, they're first offering was largely based on covers of American blues and doesn't represent them hitting full stride. Same full stride scenario could also be said for great bands such as Zeppelin, Tull, Aerosmith, Talking Heads, Prince, CSN&Y etc.

Without further ado here is my list:

1. Yes - "Fragile" (Unbelievable debut album. Ushered in a classical sensibility to Rock music that hadn't been tapped into as deeply prior to their arrival on the scene. The muscianship and composition on Fragile is stunning. I put this album as number 1 on my list because of the incredible muscianship and maturity of this first offering)
2. Steely Dan - "Can't Buy A Thrill" (Damn near a flawless debut album. The Dan's influence was huge and made it difficult for critics to even figure how to categorize their style of music)
3. Chicago "Chicago Transit Authority" (Wham they came out of left field and combined horns, percussions and hot guitar licks the likes of which the music scene hadn't witnessed before. Right out of the gate their debut album sounded like it was a veteran work of art)
4. Nirvana - "Nirvana" (What can you say about this debut? It was a solid musical offering with a huge impact on music. Their debut was an invitation to the Grim Reaper for Old School and Hair Spray rock bands. It's influence is still being felt to this day)
5. The Doors - "The Doors" (Unbelievably good debut album. Light My Fire is one of the best Rock songs of all time IMHO. Right out of the gate The Doors brought a style and sound all their own)