I don't think I can rank my favorite animes. But as for old classics, I would have to say doraemon, dragon ball z, chibimaruko. favorite 90s anime would have to be detective conan and kindaichi shounen no jikenbo. I love detective/suspense animes.
There is one anime that I watched recently, in which may rank at the very top of my list. That is Haruhi. Suzumiya Haruhi anime is an absolute mind f**k (in a good way). I saw it the broadcast order, and then rewatched it in chronological order right after. And the movie was an absolute masterpiece. I just wish they wouldn't take this long just to release new seasons. I'm still waiting for the next season, and god knows whether that may actually happen.