I've been watching anime since the mid 90s. I usually try out most of the new anime series that come out in Japan every year. I also usually drop most of the anime that I try after one or two episodes and only follow to the end the ones that I really like.
I normally watch anime in Japanese, and almost never watch English dubs unless there is absolutely no other option (such in a movie theatre). I buy anime and manga directly from Japan with few and infrequent exceptions.
I tend to like comedy, fantasy, romance, action and adventure in anime and manga.
I tend not to like melodrama, angst, violence for the sake of violence, moe for the sake of moe, sports, and “healing” tales in anime and manga.
But there are always exceptions.
When I watch the first episode of an anime I look for:
- Something unique in the story to intrigue me
- Something that I can relate to in the main characters
- Visuals that show that the artists are putting in some effort
- A sound track that appeals to my tastes in jazz and classical music
I don't often find all of the above in an anime, but do often enough to keep on trying new anime every new season.