My current franchise has run since October 2009.
I'm on Season 43. I play out every game unless the game becomes a blowout (I use discretion here) and then sim a half inning at a time. Oh yeah, I make it easier by only playing 94 games per season.
I'm getting bored with it and have been for a while now. I'm trying to create a Mother of All Worlds template for me to use....forever. But it's so expansive that I put that process down and keep playing this franchise