The most useless money sink I've ever had in my life was honestly smoking cigarettes and drinking too much at any bar, but especially divebars since I would just drink endless amounts of cheap shit.
I had to actually think about this. I've spent countless amounts of money on hobbies like movies, video games, martial arts, computers in general, music (huge money sink, but not at all useless), etc. and I have to honestly say that those two simple vices robbed me of more money than I can even fathom. I've since quit smoking and drink much less, but I have become much smarter with my drinking choices and my taste has become more refined anyway, so I pay less even when drinking expensive top shelf because I drink less of it.
If you were given $25,000 with no strings attached with zero obligation (although choosing to do so is an acceptable answer) to pay off debt/bills, what would you do with it?