When you like/love a superhero movie/series, do you have to buy the comics? I'm only askin' 'cause I usually stick to one patricular superhero from either DC or Marvel; I'm for a DC fan.

I'm a DC fan - have been for decades - so I already read the comics for the DC heroes. As far as Marvel goes, I'm a huge fan of the X-Men movies - but I haven't read an X-Men comic since about 1985; and I like some of the MCU - but again haven't read any of those characters comics since the mid 80s. So no, it's not essential.

You don't have to. Sometimes I've already read the main story arc on which a film is based, sometimes I'll read it afterwards if I enjoyed the story and want to know more. Films cut out a lot of details or change things entirely, so reading the source material can be like having a brand new experience. But it's really up to you.

If you're a DC fan, my suggestion is to read most anything before or after the NEW52.

This isn't superhero-related, but I purchased the entire Sin City books after watching and owning the DVD. After watching and owning the first two seasons of the Boondocks, I purchased or borrowed the books containing the collection of comics.

For me, I like to check out the written/graphic original source to see if it was as good as the show/film.