Hold onto your butts. Jurassic Park

For me it is really close between E.T., Raiders of the Lost Ark, Jurassic Park, and Catch Me If You Can.  In the end I chose Jurassic Park.  I saw it (and loved it) the day it released in theatres, but I think I've gained a greater appreciation for it since the Jurassic World movies have come out.  Nothing beats the original.

Jurassic Park, forever

He has an excellent filmography, but Jaws still remains one of the top films that I will stop what I am doing and watch through to the end if I pass it while flipping through channels. Within in the past couple of years, I even went to see it at a local theater when they play old movies on Saturday and Sunday mornings.

5. Close Encounters of the Third Kind
A thoughtful, profound, slow-burning science-fiction tale with an incredible climax

4. Raiders of the Lost Ark
A rip-roaring homage to 40s-era serials with style, humor, romance, thrills, and chills to spare

3. Jaws
After Psycho, probably the best horror film ever made. A heady mixture of suspense, adventure, and terror, with one of the all-time great scenes in movie history (Robert Shaw's U.S.S. Indianapolis monologue)

2. E.T.
A beautiful, tear-jerking, thematically-rich fable

1. Schindler's List
A masterpiece that I'd rank as the best movie of the 90s. Extraordinary writing, acting, cinematography, editing, and production design.

Schindler's List by far, this is not only Spielberg's best, but one of the best pieces of cinema of all time.

While I wouldn't say its his best, one of his most overlooked and underrated films in my opinion is Duel.

Most people have never heard of it; it's kinda like a proto-Jaws with a killer truck on the road instead of a shark. It's one of his earliest works and while low budget is a great example of how to do a lot with little.

You forgot the best one catch me if you can, runner up raiders of the lost ark.
I am sorry to say it but jaws has aged poorly I watched it recently the soundtrack sounds almost like a Disney movie it has a very low budget feel and there are many silly moments, a clear case of style over substance.
Overall I think Spielberg is a bit overrated but he still has some really good movies.

His cinema is fantastic.

Unfortunately, he's best known for his blockbusters.

I am not really a fan of Steven Spielberg. His movies come out as superficial to me. This is especially a problem for his more serious stuff, like Schindler's List and Saving Private Ryan. His characters are just not interesting to me.
He does have a handful of movies I enjoy though, mainly from the early 2000's, Munich, Minority Report, Catch me if you Can and my personal favorite: A.I.