Thanks for the tips guys. Will definitely check these out. Danganronpa or 999 first?
IMHO, 999 is the far better game (they're my top 2 franchises though). So I'd say go with Danganronpa, especially since 999 is for the DS and definitely play it on a DS (even a second hand DS, DS Lite, DSi or at worst a second hand 2DS will do, but play it on a DS). Danganronpa's the first game to try if you want to play on Vita. Overall 999 is better but since you want to play on Vita, I'd say get Danganronpa. The series is notoriously easy to get spoiled on by the way, so don't even google anything from Danganronpa (Zero Escape too, but a lesser extent).
Both Danganronpa and Zero Escape (999&VLR) are receiving sequels in 2016 too (don't look Zero Escape 3 up, the premise has spoilers), ZE3 is coming in Summer and will be English whereas all we know about Danganronpa V3 (Danganronpa 3 is different, DR3 is an anime and everything about it is a spoiler for the first Danganronpa) is that it's coming to Japan in 2016, so it'll likely be released in English by 2017. Danganronpa also has a canon third person shooter spinoff called Danganronpa Another Episode, the whole premise of this game is also a DR1 spoiler so don't look it up.
TL;DR: Unless you have a DS already and willing to start 999 there before moving on to the Vita afterwards, Danganronpa is the better first choice. Danganronpa is easy as all fuck to spoil, so play the first before looking ANYTHING up about the series including plot premises of other games and character names. Virtue's Last Reward is the GOAT. Don't play VLR before 999. VLR also has a 3DS version but it has a dangerous save glitch and is lower res.