Return of the Living Dead - awesome, awesome, and awesome. I've seen it about a bazillion times and it never gets old for me. I hate how Robert Kirkmen trashes this movie on his Walking Dead intro. We get it, you love Romero's films but this film has its own place in the zombie genre. Anyways, its got a beautiful atmosphere with 80's cheese/comedy to compliment the creepiness. The punks were awesome too.
Is it part of a bigger series, e.g. are there prequels etc. for it?
There's a very decent sequel; Return of the Living Dead Part II
Followed by a very mediocre sequel (but still entertaining if you're a fan by this point) Return of the Living Dead Part 3
Everything after that point is straight to dvd garbage that's not worth mentioning.