2. Say Something - a Great Big World
When this song came out, everyone on YouTube tried to cover it. I think very few succeeded. There's just this raw vulnerability you need to have in your voice to pull this song off and Pentatonix definitely does it justice. Kirstie Maldonado takes the lead in this cover and I think her voice is SO beautiful. I could keep this cover on repeat all day long. P.S the video has nearly twelve million views!