films like this...

The Wisdom of Crocodiles (1998)

Splice

Near Dark

Let the Right One In (it is worth mentioning a hundred times)

Not exactly like Spring, but I've recently watched two modern, very high quality horror films that earn it on the same qualitative level as Spring.

"It Follows" takes a very interesting horror concept and exploits it for a maximum, slow burn type of dread.

"A Girl Walks Home Alone at Night" is not a hybrid drama/horror like Spring or It Follows. This is straight up horror. But it's also incredibly stylized without sacrificing an ounce of substance. It's rockstar filmmaking mastery. This female director may be the next Quentin Tarantino.

The Hunger (true, it screams eighties but the story if fascinating)

Byzantium

Here are some movies that include plot elements similar to Spring:

1. Cat People (1982), or to a lesser extent, the earlier 1942 version - a young woman turns into a killer leopard, from time to time.

2. The Hunger (1983) - a female vampire lives for centuries, using young men.

3. Wings of Desire (1987), or its remake City of Angels (1998) - a supernatural being gives up its immortality for Earthly love.

4. Let the Right One In (2008), or its remake Let Me In (2010) - an ordinary boy starts a friendship/romance with an ancient vampire who looks like a girl.

I suggest Possession from 1981 (7.3) with Isabelle Adjani and Sam Neill
http://www.imdb.com/title/tt0082933/