There are so many to choose from, which one is the worst is very hard to determine. From completely insane nonsense like the ontological argument to those that just ignore that they would apply to every other religion equally like Pascal’s Wager there is a lot of competition.
I guess that is bound to happen when all arguments are far from good, they have to cluster around the ‘bad to worst’ part of the spectrum.
When little baby mindbleach still figured the religious hypothesis deserved a fair shake, I bought and skimmed an apologetics book. I think the moment I gave up was reading ‘the argument from magic’ that said you can control matter with your mind. Namely: your hand.
There is a subtle but crucial difference between “come the fuck on” and “you’ve gotta be fucking kidding me.”