The Fresh Prince of Bel-Air kickstarted the career of Will Smith and had a kickass theme song.
Will is dead all along, and Bel-Air is heaven
From the original post made on /r/fantheories way back in 2012:
'Will actually died in the fight on the basketball court on West Philly.
The taxi driver is actually God, who drives a "rare" cab. He takes Will to heaven, where he works out all his issues with his wealthy Aunt and Uncle.
Will only sees his mother and father on special occasions, because that's when they come to visit his grave.'
Some expansion on this theory comes from the show's full theme:
I got in one little fight and my mom got scared
And said you're movin' with your auntie and uncle in Bel-Air
Here, Will sustains injuries in the fight that will soon prove fatal, and is hospitalised. His mother is distraught, but has to accept that her son will die.
I begged and pleaded with her day after day
But she packed my suitcase and sent me on my way
She gave me a kiss and then she gave me my ticket
Put my walkman on and said I might as well kick it
He continues to fight back to stay alive, but eventually his mother allows his life support to be turned off and he dies.
First class yo this is bad
Drinkin' orange juice out of a champagne glass
Is this what the people of Bel-Air live like
Hmmm this might be all right
But wait I hear they're prissy, bourgeois, and all that
Is this the type of place that they just send this cool cat?
I don't think so I'll see when I get there
I hope they're prepared for the prince of Bel-Air
As Will's soul is taken upward, he doubts that he would be worthy of Heaven, despite the feelings of initial bliss he receives.
Well uh the plane landed and when I came out
There was a dude looked like a cop standin' there with my name out
I ain't tryin' to get arrested yet I just got here
I sprang with the quickness like lightning disappeared
He finds he has been chosen for Heaven, and takes his chance before they change their mind.
The rest is self explanatory. He enters God's rare cab, and is brought into heaven. And they are all kings in the Kingdom of God, so the "prince" title is appropriate.