I really like the Vocaloid Ruby cover art haha, and this is a really good list to start off with! I would recommend looking at more songs from the producers who wrote some of these songs, like JesusP [more songs include: Death Should Not Have Taken Thee!, Development of Amazing Apps, Remote Controller], GigaP [Electric Angel Remix, Resonate, Childish War], Scop [Irony, Tokyo Retro, Crier], Emon [My Feeling Emotions, Too Cute, Dreaming Chu Chu,Shake it!], and Hachi [Donut Hole, Panda Hero]. I'd also recommend at looking at Kzlivetune [Last Night Good Night, Tell Your World, Yellow, Weekender Girl], 40mP [Karakuri Pierrot, Time Machine, Love Trial, Left Behind City], Suzumu [Heart Connect, The World's Lifespan and the Last Day, Shoddy Utopia Policy] and MitchieM [Freely Tomorrow, Viva Happy, Ageage Again] ...Sorry if that's a longer list than you were looking for, I didn't mean to make it look so daunting :P