I've recently gotten LoZ:MM3D on 3DS and FFVII on steam and I was wondering if there was one that you guys think I should complete first. I plan to nearly 100% one game before moving on to the other and I'm about an hour into each. I can't decide which to beat first. Thanks all

Well, in addition to Majora's Mask being one of my favorite games of all time, it's probably the quicker of the two to 100%, so if that's your stipulation before moving forward, it's probably the best to start with.

Majora's Mask is the better choice of the two here. Not because I'm a Zelda fan, but as Dave has said here, it'll be the quickest of the two if you plan to 100% each title. It shouldn't take too many hours of your time to do. FFVII is worth hours upon hours of play time. It could be a good, long while before you 100% it. If you put that first, you might find yourself putting off Majora's Mask for a long while, especially when you take into consideration any work, school, or events that keep you away from games for several hours at a time.

As a big Zelda fan it'd be hard for me not to recommand Majora's Mask first