Another singer you may know from a cover she performed with JubyPhonic a while ago, Rachie also specialises in English covers of Vocaloid and anime songs. Interestingly, she's also fluent in Indonesian and has recorded some beautiful covers in that language too.
5) Mairieux
The animation may be simple but don't let it fool you. This song is contemplative and heart-wrenching, not least of all because it's relatable for so many people.
4) 1/6 - Out of the Gravity
This song is part of a massive collaboration to cover some older Vocaloid songs. The rest of the videos can be found here. It's worth paying attention to the lyrics in this one. They tell such a sweet story and Rachie's voice really brings it to life.
3) Distant Fields
I never get bored of this song - it's full of so many emotions, the animations are by Chris, an amazing artist, and Rachie's lyrics are awesome.
2) Eine Kleine
This piece is so touching and singable! I swear, this gets stuck in my head all the time. XD The Kagerou Project is one of my favourite song series, so the music video being based on that was an added bonus for me.
1) Goodbye, Ms. Flower Thief
In my humble opinion, this is Rachie's best cover so far. She just sings it so well, there's nothing I'd want to change! The lyrics are a bit odd but it's more about the mood they create. Putting that aside, it's just so much fun!