A Link to the Past, Link's Awakening or OOT3D.

A Link to the Past is the best choice imo. It's the Super Mario Bros. 3 of the Zelda franchise. It made a great base for all of the future games.

Lol. I meant 2D games like Oracle Games, A link to thePast ect. Nothing else intrests me and I barely managed to finish LA since it felt so old and so clunky and had practically no story. I swear I only read like a paragraph of story in that game... (still an 8/10 btw )

At the momtent I'd say Wind Waker HD is the perfect game to start with. It's visually beautiful and combines rock-solid gameplay with a good story.

I honestly feel like OOT 3DS is not the best place to start with this because, while it's certainly a stellar game, at some points it drove me nuts due to the outdated savingmechanic and the stiff camera.
Otherwise it holds up fantastically, but if I imagine someone with absolutely no Zelda expierience, I wouldn't recommend them a Zelda with outdated mechanics to start on.

I would go with TP (GC) on Dolphin, or TP HD on WiiU for most people. Probably SS or WW for kids.

The 3ds version of ocarina of time. I wouldn''t opt for a link to the past because it wasn't until links awakening that zelda got it's quirky characters and dialogue that I associated zelda games with. For 2d Zelda get a link between worlds and for 3d go for any of the remakes. Oot3D, MM3D or WWHD. They're relatively uncontroversial, great and show you what all the fuss is about.

Ocarina of Time if you like modern games. Link to the past if you're into retro games.

The Legend Of Zelda, for NES.

I'd say either A Link to the Past or Ocarina of Time, since they're laying the foundations of much of the series's lore, as well as much of the core gameplay mechanics for 2D and 3D respectively. The very first game obviously also layed down some of the basics, but that one's extremely difficult and would feel obsolete for a modern newcomer. I suppose something could be said about playing Skyward Sword first as well, since that one's the first chronologically.

I'd suggest first-timers should stay away from any of the direct sequels in the series like Majora's Mask or Link's Awakening until after one played the 'primary games', even though they're absolutely brilliant, I think they'd be a confusing start. Not that you'd have a bad time obviously though.

Definitely, majority of nowadays gamers will turn of that game just after few minutes. :)