Anime is a very diverse medium and there are many stories of people getting into anime one way or another. I was watching Card Captor Sakura over the holidays and thinking about it. I really liked CCS, but it's something I never would have thought about watching even just a few years ago.
Something that blogging and keeping track of what I've watched and when has allowed me to do is to take note of which anime were instrumental to introducing a new genre to me and how I got roped into watching something that I wasn't really inclined to watch.
Some gateways are fairly obvious. Ouran High School Host Club is a pretty common entrance into shoujo romance, because the first chunk of it is played off as self-parody. By the time you're halfway into the story in the manga, it's become a shoujo series again and it's too late, because it's already got you.
Some gateways are not so obvious. Clannad is probably my favourite show, but it was in a genre that I absolutely refused to watch. What got me to watch it? It was because I watched 5 Centimeters per Second. Even though 5 cm/s isn't the same kind of anime, the association between that and nakige was pretty strong for me.
Some gateways are dumb. How did I start watching magical girl shows? Because people were hyping Nanoha as an atypical, explosion-packed magical girl show. But even that wasn't enough for me. What finally pushed me into it was Masaaki Endoh's (from JAM Project) cover of the Nanoha A's OP, ETERNAL BLAZE.
What were the gateway anime that opened up an entirely new kind of anime for you? What are the shows or movies you would make other people watch to trick them into liking things they might not like?
(Also, this is not for talking about how you got into anime, because I'm sure we've beaten that horse into the ground already.)