Procol Harum’s first US album starts with “A Whiter Shade of Pale.” It had been a smash hit so they led with it.
Their UK album starts with “Conquistador,” another one of their classics, though not until it was recorded live.
The German version starts out with “Homburg,” also a great song.
I go one further; Best first line off the first song of the first album.
“Jesus died for somebody’s sins, but not mine!”
“Gloria” from “Horses” by Patti Smith.
Excellent choice.
The Go Go’s debut Beauty and the Beat started out with the catchy tune Our Lips Are Sealed. Sure, its pop, but pretty decent pop.
I will not let you use “pop” as an implied pejorative. That’s a fantastic song. I’m going to put it on right now, in fact.
The first track on Rockpile’s debut (and only) album is a fun track called Teacher, Teacher. But they were together for a bit before that backing other groups.
In a similar house band vein, Booker T and the M.G.s were the house band for Stax. The first track on their debut album is probably their most famous track - Green Onions.
You by Radiohead. Sure, it was completely overwhelmed by the next song on this album, but it’s a strong opener to their catalog.
A few I like that I don’t think have been mentioned yet.
Say what you will about who & what U2 has become, they came out of the gate from Ireland on fire, perhaps even an unforgettable fire 
Interpol’s “Turn on the Bright Lights” was set up in one of the Employee’s Choice Listening Stations at my local record shop (RIP) sometime back in the fall of 2002. The first track (“Untitled”) sold me.
Those are excellent choices.
Fairport Convention’s debut album, Fairport Convention, opens with “Time Will Show the Wiser.” Definitely a strong introduction.
If we allowed for the subsequent debut albums for each of the members of the band (and combinations thereof, including spouses), we’d have a lot more very good contenders.
Tangential, but the podcast “Life of the Record” has a terrific episode on the making of “I Want to See the Bright Lights Tonight”, narrated by Richard and Linda (or Linda’s daughter reading her notes, IIRC, because of her misophonia).
The opening track of IWTSTBLT is a very, very strong contender for favorite opening track on a debut if we allow it to be the debut of Richard and Linda as a group. I believe one critic stated that there is no track on the album “…that is less than luminous.”
Unfortunately, this was not the first album that Richard and Linda did together. As The Bunch, Richard, Linda (Peters), Sandy Denny, and others released an earlier album, Rock On. For this reason, I’m reluctant to consider it a debut.
I wasn’t arguing it for a debut, I was letting you know there was a cool podcast episode out there based on your interest in them.
Thank you! Sorry. I was already aware of the podcast, so I misinterpreted your comment. My gratitude and apologies to you.
No problem! I’m glad you’d found that, it’s really interesting hearing them talk about it so many years later.
Chuck Berry’s first album was After School Days, released in 1957. The first track was the hit School Days. But Berry had released several singles starting in 1955, the first of which was Maybelline.
Marshall Tucker Band’s Take The Highway.
Like some of the other great suggestions in this thread, it’s an example of a debut track clearly showing what the band is about.