DS3 is harder than the rest simply because the combat is quicker and the enemies are full of cheap combo moves. Honestly gameplay vise my favorite is SotFS followed closely by DS1 remastered with DS3 being a distant last. Lore vise though I don't get the hate some people had for DS2. Yes, it does its own thing and isn't a direct sequel and yes it's not as good story vise as DS1. But it's still a bloody solid game that beats almost anything on the market other than the original. And it really didn't deserve all the hatred it got.