They get bored so they buy an island and hunt each other for sport.

"The Gang Blows Up"

...on a Tuesday at 3:43 PM

They all overhear that the area their bar is in is worth a ton of money in real estate so they all try to figure out how they can prove they're the sole owner and find/forge deeds so they can sell the bar and claim a fortune, spend the whole episode screwing each other over, only to find that Frank already sold the bar and fled south to enjoy his golden years in Mexico and upon their return to the bar's street, are shown that it's now in the midst of being demolished along with other buildings on the block to make way for a ton of cute shops and restaurants causing them all to just stand there and wonder what to do next.

2 guns, 6 boobs and they're all on the same team.

I think the gang would all have to die. They have already somewhat teased it when they were on the sinking cruise ship. I am sure they could dream up an outlandish way for it to happen.

The Gang ends crime in Philly

And then he smells crime again, he's out busting heads. Then he's back to the lab for some more full penetration. Smells crime. Back to the lab, full penetration. Crime. Penetration. Crime. Full penetration. Crime. Penetration. And this goes on and on and back and forth for 90 or so minutes until the show just sort of ends.

I think it would be very on-brand if they just did a regular episode and didn't reference it being the final episode. Then have a mid-credit scene where the actors break character and realize they forgot it was the finale

"The Gang Gets Cancelled" is the obvious answer, but I'd like to see them try something more audacious and really stupid.

"The Gang Goes to North Korea" maybe.

Maybe they all go on trial and end up in prison together.

Frank dying, and the Gang then having to deal with that, planning his funeral and the typical things that TV episodes of this nature have, except subverted as is tradition with the show. Dee and Dennis trying to get his DNA because the Jew Lawyer, obviously the executor of Frank's estate, tells them that since they're not his real kids they're not going to inherit everything. Charlie likewise trying to do the same to prove that he is Frank's son to get his hands on the money. Throw Franquito into the mix as well.

"The Gang Throws Frank In the Trash"

This is basically the premise of an existing episode

Oh, is it? It's been a long long time since I've watched all the seasons so I guess I forgot. Heh.

Frank wakes up from a terrifying fever dream, 40 years younger, in a chair at a desk in a taxi dispatch office. Wipes the drool from his mouth, on his worn out vest. He then mumbles all sorts of curse words as he steps down from the office into the taxi pool, yelling random directions and insults at Jud Hirsch, Marilu Henner, Tony Danza and Christopher Lloyd who are all in character and trying to make sense of his troubles.

That episode where they all almost drowned would have been a good ending but I'm glad it continued. I'd like to see everyone die in the finale. They've totally earned their place in Hell. Hopefully not for many years yet though.

"The Gang Goes To Prison"

Why do they blow up? Because Cricket planted a bomb under the toilet seat with the word BOOM written on the toilet paper!

Enter Mel Gibson and Danny Glover as cops.

They all die throughout the episode one by one and only Frank is alive at the end. He says what am I gonna do now so he grabs the noose and looks up and says I’m coming Charlie.

Can it end with a Groundhog Day theme to it where you end up at the first episode and watch the whole series again?