Joey was the obvious / only choice but it was badly misjudged... if it had been handled more competently it could have been fine
. Although I'd say the first season, at least, would have needed a significant number of guest appearances from other Friends cast members (e.g. Ross and Rachel visit Joey, Joey visits Monica and Chandler and outstays his welcome, Joey on some random trip to a theme park with Phoebe... etc)
I could see a Monica and Chandler spin off NOW with like teenage kids... but that's not really possible... as Matthew Perry looks homeless and Courtney Cox had too many facelifts and looks ****ing terrifying.
Of all of them, only Matt LeBlanc and Jennifer Aniston have aged well. David Schwimmer and Lisa Kudrow have aged "normally" and yeah... the other two...
.