Nobody has recomended Meat Loaf & Stoney?
Meat hasn't got an awfully big back catolouge.
Off the top of my head, albums and live releases as follows............
Meat Loaf & Stoney (very different to what you would think of as Meat Loaf).
Bat.
Dead Ringer
Midnight At The Lost & Found
Bad Attitude
Blind Before I Stop
Meat Loaf Live (recorded 1987 at Wembley)
Bat II
Welcome To The Neighbourhood
Live Around The World
The Very Best Of (features 3 new songs)
Storytellers
CHSIB
Bat Live with MSO
Bat III
3 Bats Live
HCTB
Every album has it's plus points (some more than others, but that is down to personal opinion).
If you had all the albums on the above list, you would have the vast majority of Meat's musical work.
there are rarer one off tracks such as B sides and songs done for various other albums and collections, but collecting his albums is going to give you the best base for your collection, as well as giving you a larger ammount of Meat Loaf songs sooner.
Compilations are something you may wish to avoid if you just wish to collect Meat's music.
There are great songs on Rock N Roll Hero (if it's the one i'm thinking of.There are at least 3 compilations called R&R Hero) but you can buy 10 Arista compilations and still not own all the songs on the three Arista albums releases.
That said, there is nothing at all wrong with a few compilations, or even every one you can find (they can also make a good collection in their own right) just as long as you remember that the albums are far more important and efficient method for having a comprehensive collection on Meat music.