I think Attack on Titan is my favourite in terms of storytelling, worldbuilding, visuals (when its not CGI), characters and so on, but the anime that has had the most impact on me is definitely Evangelion. From a traditional storytelling perspective I don't think Evangelion is very good, but its so personal and it realises its themes so well that I have to love it. Seeing Shinji work through his depression and realise that taking the risk of being hurt is a part of being loved made a big impact on me when I watched it, because I was in a very bad state at the time.