If I were you, i'd go with the 3DS (preferably the "New" 3DS). The 2DS is cheaper, but overall, it's much more inferior compared to the regular 3DS or the "New" 3DS (especially to the "New" 3DS). The "New" 3DS has the clamshell design, 3D capabilities (with enhanced 3D face-tracking capabilities), the c-stick (which, if you're playing a game like Monster Hunter 4 Ultimate, it should be very, VERY helpful), built-in amiibo support (if you're not interested in amiibos, ignore this), stereo sound (2DS only has mono), bigger screens, longer battery life, etc. Even if you just look at the regular 3DS, it has 3D capabilities, the clamshell design, stereo sound, longer battery life, and bigger screens (only bigger if you get the XL) while the 2DS simply doesn't.
Overall, I think it really depends on how many games you want. Are you only looking to buy 2 or 3 3DS games to play, or are you planning on buying many 3DS games? If you're only planning on buying 2 or 3 games, just buy a 2DS. If you're planning on playing a lot of 3DS games, purchase a regular 3DS or a "New" 3DS.