Cpt beyond debut is incredible and a mix of genre, the subsequent album left me wondering what happened. I also like dust featuring the Ramones drummer doing some impressive non punk beatsBoston's debut album by definition, ensures that everyone KNOWS exactly what you are driving at. It was that good overall and that encompassing. And commercially at the top of the chart. So it defines the genre.
The only one that comes as close to this threshold for me is Jimi Hendrix Are You Experienced. There are a lot of other great DEBUT albums, many that are mentioned above, but few received the amount of air play across ALL all tracks as Boston.
Likewise, every tune on AYE is a classic.
The other criteria that I'm not sure is being applied here is the DEBUTE ALBUM ENDS UP REGARDED AS THEIR BEST. Boston never had as good an album as their first (IMO). Most of the groups - Led Zep, Doors, Beatles, Sabbath, Hendrix, CSN, Cars ....mentioned by posters in this thread - went on to greater glory afterwards.
Great DEBUT albums with the largest number of well known song tracks contained therein might also include....... Lynyrd Skynyrd 1st, Heart - Dreamboat Annie. Anyone ever listened to Captain Beyond's debut album? That one ....... f'in blew me away.....