so what are the movies that you thought would be good going in, but came out just wowed?

Batman Begins
Kiss Kiss Bang Bang

are two that come to my mind. know there are more...

Rise Of The Planet Of The Apes

Not to be confused with

Movies you're surprised you liked?

Gravity

Really? Were your expectations really low?

I do like the film but it's got scripting issues galore that sadly not even the direction can help it. Ape wise...it's pretty solid. Those humans though...ugh.

Second Hand Lions. A blind buy with really no expectations. Was very pleasantly suprised and have recommended it to MANY people.

Recently, it would have to be Maleficent. I really liked the film.

Safety Not Guaranteed. No idea/expectations going in. Really enjoyed it.

Cap 2 (Considering that I thought the previous movie was extremely mediocre)

Happy to hear this as you seemed to already have some pre-release bias against it. Haven't seen it, but will likely blind buy it when it hits disc.
The more people that initially dismissed it, only to enjoy it, augers well.

The Lego Movie, as noted in that thread.

Real Answer:
I went to see Election at the dollar cinema to kill time waiting for my laundry, expecting it to be on the level of Lost and Found or some other generic sit-com and was blown away by how funny and insightful it was. Great movie. Still one of my favorites.

Joke Answer:
The Phantom Menace. There was actually a lot of hype around this movie before it came out. I figured it would come no where close to capturing the magic of the original trilogy and boy, was I wrong. I had my jaw in my lap the entire movie, pumping my fist in the air with excitement, shouting "Yes! Yes!" as scene after scene topped itself with intrigue and action -- grounded by fascinating characters traversing a tightly plotted narrative. When the movie was over, as soon as I caught my breath, I RAN to the nearest store to get myself a Jar Jar Binks T-shirt.

The Matrix - Judging from the trailers and TV spots I'd seen, it looked like a silly Keanu Reeves sci-fi movie along the lines of Johnny Mnemonic. My friend dragged me to it and I was blown away by how awesome it was. Of course, the sequels had the exact opposite effect.

The Sixth Sense - Looked like a generic ghost story and I was hoping it would at least be entertaining if not completely forgettable like The House on Haunted Hill remake, but instead, it turned out to be one of the best supernatural thrillers I'd seen in years and even got me with the twist ending.

Super Troopers - Looked kind of funny, turned out to be freaking hilarious.

Black Dynamite exceeded my expectations. Cracks me up every time I watch it.

True Romance- I rented it as a just another movie to watch on a snow night in high school. It turned me into a Tarantino fan.

Recently:
Robocop (2014)- Taken as it's own thing and not trying to compare it to the original film I thought it was pretty enjoyable. The original film is a classic but in some ways I actually thought the new film expanded on some of the ideas from the original and had some things I liked better. I really don't view the film as a remake but more as updating the concept and putting a slightly new spin on it.

Captain America: The Winter Soldier- I didn't expect it to be bad but I also didn't think it would be nearly as good as it was. I didn't love the first film but think that this one is one of the best Marvel efforts to date.

Edge of Tomorrow.

A Few Good Men- I remember seeing the trailers in 1992, and thought it was going to an over the top acted movie and the big stars would make up for a lame military story. I kept thinking why would they hire Demi Moore for a movie like this? And I also remember seeing the Tom Cruise/Nicolson court room bit in trailer, "I want the truth..." and thought it came off as too much.

Then I saw it an absolutely loved it, and it is still one of my favorite movies to this day. I thought the movie was perfectly cast and I had to eat crow as Demi Moore gave a good performance in that next to Tom Cruise. And of course Jack Nicolson steals every scene!

Wall Street. Figured it would be boring but it sucked me in and I really enjoyed it.

Two movies immediately come to mind.

Back when The Apostle came out, my then-girlfriend was all gung-ho to see it. From the trailers, it looked boring to me. Ended up loving it.

The other is The Sixth Sense. I was all caught up in Blair Witch hype at the time (it helped that I lived within spitting distance of Burkittsville, Maryland then) and was bummed when the newest Bruce Willis movie trumped it at the box office. When I finally got around to seeing Sense because a friend recommended it, I was blown away. I'll never forget the all-over goosebumps the ending gave me. It also made me fall in love with the name Cole, which I gave to my son (almost 10 years later).