First of all...
Anime & Manga Stack Exchange still accepts some kinds of identification requests, particularly if the series is known:
Episodes from a known series (this includes some anime/manga-style series of non-Japanese origin)
Cosplay/merchandise/itasha, but with some exceptions
Note that this list is not intended to be exhaustive. The above list contains the types that are known to be acceptable by the community.
If you are still not sure if your identification request is acceptable here, feel free to post a new discussion on the meta (requires 5 reputation). If you have enough reputation to participate in chat (requires 20 reputation), feel free to join our chat room. Otherwise, just ask the question, and the community will evaluate it naturally.
But wait...
If the series has some sci-fi/fantasy elements, our sister site Science Fiction & Fantasy Stack Exchange accepts it, but please ensure to follow their guidelines first!
For a more general manga/(light) novel, our sister site Literature Stack Exchange accepts it, but please ensure to follow the guidelines on the tag info and their meta first!
If you have an image of an anime/manga/character, try doing a reverse image search: Where is this picture from? How do I use Reverse Image Search to find the source of an anime/manga image?
If you feel adventurous, you can also try searching through various databases based on criteria such as genre, etc.: What databases and listing sites exist for anime, manga, etc?
Otherwise...
- MyAnimeList has anime identification and manga identification threads
- Animesuki Forums for general anime/manga/game identification help
- Baka-Updates Manga for anime & manga identification
- Reddit has some subreddits like /r/anime, /r/Animesuggest, /r/manga, /r/tipofmytongue, etc. but please read the rules on the sidebar of each respective subreddit beforehand!
- Quora has 'Anime Identification' topic
- TV Tropes has "You Know That Show..."