One thing that certainly gets a bit on my nerves is going to the forum games and not even making a slight attempt at playing the rules or doing something a little creative (within those rules). It's like showing up at a poker game with uno cards and expecting to be taken seriously.
The Fate anime’s biggest flaws are how often they assume you already know the story of the characters they are using, and their servant forms. While it’s not like the show doesn’t develop things outside of that, a lot of its coolest and most interesting aspects all come from how the legends of the individual heroes are translated into their servant forms, as well as how those legends and powers play off one another. Without that info, a lot of the challenges, actions and solutions will simply seem to come out of nowhere.