I'm not exactly new to the Pokemon franchise. I played the home console Pokemon games on the N64. Pokemon Stadium 1 and 2. I also owned Pokemon Snap (even though its not a true Pokemon Game). I had a Pokemon GBA game too which I had fun playing with. I played Pokken but didnt like it.

But I think I'm  ready for another traditional Pokemon game now. There's a lot of Pokemon games for the 3ds and i dont know which one to get!! There's the X and Y, The saphire and the other game.. and then there's Moon and Sun coming up... Which game should I get? I want the best Pokemon Experience possible   

I know these aren't 3DS games per say but they can be played on one :P
I'd like to recommend Pokemon BW/BW2 because I think that they're some of the best in the series when it comes to content and story. There's a lot of different Pokemon to catch too.

Pokémon Shuffle and Pokémon Rumble World are pretty addicting free games. StreetPass FTW!

Pokémon Red/Blue from the 3ds virtual console store.

Omega Ruby/Alpha Sapphire are my personal favorites on the 3DS, but I thought that XY were pretty terrible for Pokemon games. BW2, RBY, HGSS, and Pokemon Mystery Dungeon: Explorers of Sky are also excellent games.

IMO Diamond/Pearl was the best generation. Other Pokemon games are solid though, however X/Y is pathetically easy by an absurd amount.

I'd have to agree with MohammadBadir, B/W and (especially) B2/W2 are really fantastic games in the series and a great Pokemon experience. I'd choose them if I were you, only if you don't mind not having the latest mons', moves/abilities or the Fairy type to play with though.

But if you're talking specifically about 3DS games I'd say wait until Sun and Moon to decide on which to get but if you really can't wait to play, ORAS is definitely a better choice than X & Y.

Since you are talking about getting the best experience, i believe you are talking about gameplay options and graphics. If this is what you want, maybe waiting for sun/moon is the best option.

You can have some sort of experience on the 3DS with every single Gen in the series. So I'd recommend starting with Red or Blue and working your way through.

Dont play 5th gen (B/W). X and Y was made to be a 'revival' experience, but it also gets pretty easy later on. If you played during gba days then omegaruby alphasapphire might be up your alley