Alpha Sapphire. When I got Red/Blue, my parents didn't put the nametags on the presents so by chance I opened Blue while my brother got Red. I suppose they thought I'd like the blue version again, so they got me Sapphire, haha.
Alpha Sapphire despite liking Groudon's new look better (oh so cool!) just I have some kind of weird attachment to Kyogre for some reason, maybe because it was the first Pokemon I hacked when I was a kid because I only had Pokemon Diamond... (just made one appear, no stat changes or anything)...
But if I have to decide like how I did for X and Y (Liked both mascot legendaries) I'll decide on what megas there is to offer. (Mewtwo Y <3)
Leaning towards Sapphire, mainly because it just makes more sense for Team Aqua to be the ones hiding out near Lilycove and not Magma. (Seriously, if GF is going to do that then the Magma version of the hideout at least needs to be aesthetically different.)
Unless the remakes do something that'll make me want to buy both games (which I would gladly do), I'll choose Omega Ruby. I went with Ruby back then (played through it seven times) and I'll align myself with it once more.
I am still undecided. I am thinking of getting Omega Ruby, because I prefer rubies, I like the colour red and Omega Rudy sounds good. However, I never played the original Pokemon Ruby, I played Sapphire and Emerald, so I am wondering whether I should get Alpha Sapphire to shadow the footsteps of my past. That and I liked the constant rain pouring down the Hoenn region when Kyogre was awakened.