Socksniffer
It is really good. The MC gets isekai'd to an alternate version of himself in different franchises with each death. Author handles the franchises well, even if you don't know them you will enjoy it. no need to research them. Greatest pro is the MC acts rationally and doesn't suffer from the average isekai protaganist curse of being a moron. Alas he also doesn't get isekai plot armor and will die the moment he lets his guard down. MC keeps things from previous worlds but is slowly earning his well balanced normal items/powers. For example at first he is limited to normal items/weapons but is now potentially acquiring superhuman abilities(within reason). Either the world level slowly increases, or it increases with his tier. Not lacking on humour and a likeable mc. Highly recommended.
One of ths best fanfic out there but the author seem like just a lazy idiot. He ask for donate donate all the time with little to no update. Im pretry sure he dont even need to ask for donate if he just keep going and writing. Same with armipotent. The book dont ask much for donate but eventually it gpt to front advertising page. He seem lack of confident about where his book can be. Or he is just want the easy money. Just begging