The list of low-budget/indie black films I'd recommend:
Nothing But a Man
Watermelon Man (I presume it's low budget - it's shot on Desilu/Paramount sitcom sets)
Sweet Sweetback's Badass Song
Blacula (yes, it's corny, but it's a fun corny)
Foxy Brown (same)
Suga Hill (same)
Abby (absolutely the same)
Car Wash
Hollywood Shuffle
School Daze
I'm Gonna Get You Sucka
The Five Heartbeats (I don't not recommended it; it's just not a "classic". There's much better films on this here list)
Do the Right Thing
Lean on Me
Boyz N The Hood
Poetic Justice
Fear of a Black Hat
The Best Man
The Wood
Soul Food
Bamboozled
Antwone Fisher
Barbershop
Talk to Me
Black Dynamite
Pariah
Dear White People
Think Like a Man

...is longer than the list of ones I've said aren't recommended:
Sparkle
Jumping the Broom
Tyler Perry's Diary of a Mad Black Woman
Tyler Perry's Madea's Family Reunion
Tyler Perry's Madea Goes to Jail
Tyler Perry's Meet the Browns
Tyler Perry's The Family That Preys
Tyler Perry's Why Did I Get Married?
Tyler Perry's Madea's Witness Protection

And the ones caught in the middle that are just sort of "shrugs" for me:
love jones
Berry Gordy's The Last Dragon (it's an awful film, but it's the kind of awful that works for "So Bad It's Good" night)
Preacher's Kid (see above)
Cover (see above)

Where's The Wiz? It was the most expensive musical filmed up to the time of its release in 1978, so it's not "low budget".

I'm going to save this to my files and repost it as necessary. Because I'm petty like that.