Best debut album

The Cars

John Prine
The Band
Hot Tuna - Acoustic 
Jackson Browne- Saturate Before Using 
Sarah Jarosz - Song Up in Her Head

Willis Alan Ramsey. Perfect album. 

Jethro Tull - This Was. Check out Steven Wilson's remixed version. I love hearing this band when they were young, just developing their style. This is primarily a blues record, a style that they ultimately abandoned. Still - listening to "Some day the sun won't shine for you", you'd swear that you could stand right up and stand amongst the band. The whole album is like that. Really enjoyable!

As an R&B lover, I'd say:

Mary J. Blige -- What's the 411
Keith Sweat -- Make it Last Forever
Lauryn Hill (solo) -- The Miseducation of Lauryn Hill
Missy Elliott -- Supa Dupa Fly (I remember seeing this in a Record Store posted everywhere, and I thought "who is she and why should I but that CD?" until I got home and listened to it.  I'm glad I took that chance.. I've loved her ever since.
 
And on another note, I really loved:
Madonna -- Madonna  (I always thought HOLIDAY would be a classic)
Nora Jones -- Come Go with Me
English Beat -- I Just Can't Stop It (my most listened to CD in college)