I'm picking Mortal Kombat if only for the original 1995 film. It's definitely partly because of nostalgia and partly because I haven't seen most modern film adaptations (haven't seen Sonic, or the newer MK film, or the new Mario movie, etc.).

............ man... i feel like this is harder than it should be, or that i'm taking it too seriously lol.
I loooove the original MK movie and the music is amazing, and yes i like Annihilation why? Because i was 8 and Cyrax does backflips.
Love the first Tomb Raider movie, love Street Fighter there's so many memorable quotes and performances in that movie and i'm not even a SF fan, i like the two Hitman movies the first is a bit more memorable but the 2nd is better overall, the live action Resident Evil films are ok they get worse with every entry but the animated ones are super good.

I think i have to say Street Fighter, i was very young my dad had it recorded on VHS and i watched it over and over, i'll sometimes load up clips from the movie on Youtube, so much of the casting is perfect, i wouldn't be surprised if "but for me it was Tuesday" is used by people who have never seen the movie, it's got a sick ass stealth boat with a gun on it.

Edit: Assassin's Creed is one of the most boring movies i've ever seen, it had some amazing stunt work it's just a shame it belongs to something so dull and uneventful, semi-related, i really like the Prince of Persia movie, actually very good, it really feels like the actors involved are having a good time.

The first MK was excellent. I remember having a great time when we saw it in the cinema (I lived in the UK in 1995, so not a 'theater'). Still, all the Sonic movies have entertained me AND my kids as a bonus.

Annihilation is my guilty pleasure even with the cast changes and even more non-sensical creative liberties, the dramatic green screen dive to the ground, and the ultra slow motion of Liu Kang... Jumping down to Raiden.

With that said, Mortal Kombat 1 is the movie to think fondly back on, considering even the video game acknowledges that movie with DLC. What I wonder from time to time is... What would it be like, if Ed Boon decided to stop using rope and spear, and actually incorporate the movie's interpretation of Scorpion's "COME HERE!/GET OVER HERE!" with a........... Uh....... Whatever that weird snake-like thing is? Not that I understand how it relates to scorpions.