Best debut album

Nobody's mentioned Eddie Moneys self titled first album. The one with Two Tickets to Paradise and Baby Hold On. The entire album was worth listening, and we played the heck out of it. Not up there with Bostons debut, but noteworthy

Jimi Hendrix Are You Experienced? Dude!

Agree with OP that Can’t Buy a Thrill is a top debut.  One could argue that the Dan’s first two are also contenders for the best opening two.  My favorite is R.E.M.’s Murmur but it is hard to argue with Are You Experienced and Led Zeppelin. And then there’s the game changers...Never Mind the Bollocks and PJ’s Ten.  

Neil Young and Crazy Horse - Everybody knows this is nowhere. (I'm skipping his first solo release which did not include the band, so technically...)

Crosby, Stills, & Nash

Can't really figure out why Boston so popular. Radio pop with handclaps?