Kingdom Hearts, I don't remember whether it was just the Disney element that put me off it, but I certainly incorrectly judged that game prior to playing it.

Destiny, I thought it looked meh, then I thought it was great fun after some mates convinced me to buy it, then a couple of weeks later I thought it was meh again, lol.

Rocket League, I respected it when I first saw it, it looked fine but it certainly didn't look like something that I'd enjoy, primarily with it being multiplayer only. Boy was I wrong, thank you Sony for giving it to me for "free".

Frequency, a mate bought it and I didn't give it the time of day, until of course I played it. I later played Amplitude to death when it came out.

Uncharted, in the early days of PS3 there wasn't a great deal of awesome games, I took a punt on Drake's Fortune because it was the big exclusive, I honestly wasn't all that bothered by the game before playing it. It was so much better than I ever thought it could be, not to mention how amazing the series became.

I imagine there's a load more, drawing a blank, unfortunately there's so much more that I thought looked great and ended up meh.

Dying Light suprised me.

It's ok, MGS2 was pretty disappointing and meh in the same because of Raiden. xD

Shadowrun on SNES. I assumed there was no way it was as good as the Mega Drive version, but in the end I found it to be much much better.

DmC

Farminf simulator 15

ACIV on the WiiU. I had started the series with ACIII and couldn't get into it.

While it did have hits in framerate - it didn't really stop the rest of my ACIV experience from being simply grand.

I really loved how you could strip away the HUD from the TV to the gamepad and the gamepad's map feature. A completionist's dream I tell you!

Resident Evil 4

Portal.

Right now I'm like "I was once underwhelmed by Portal? Whose hands are these? I don't recognize them anymore. I feel nothing."

Crash Bandicoot. Didn't look that fun from gameplay but I played Crash 1 and Twinsanity and now I love the series.