I seem to be running a five days backlog each time I answer this xD
Day 13. Favorite song from Super Junior 05.
Twins. Or OVER... xD No particular reason though; just cause they are catchy.
Day 14. Favorite song from Don't Don.
Don't Don. I'm starting to see a running theme here in my list of fav songs... Hehe.
Day 15. Favorite song from Sorry, Sorry.
Sorry, Sorry. (Yes, I always like the lead singles; so sue me) Neorago was really good as well though; but my Sorry, Sorry playcount is like, almost twice of Neorago so... xD But generally, the 3rd album is my favorite; I remember repeating the album everyday in while studying for exams in 2009 8D
Day 16. Favorite song from Bonamana.
Bonamana. LOL. Looks like I'm kinda predictable. But I also really like Shake It Up, Coagulation, Good Person, Boom Boom etc. And if you count the repackaged album, of course No Other is great. In fact, no, I think I prefer No Other to Bonamana. So there you go. :D
Day 17. Favorite solo song.
I shall be a complete Eunhyuk bias and say One Love. Though, well, according to my playcount, that IS the solo song with the most plays. But I like quite a few other solo songs, like Yesung's It Has To Be You, Ryeowook's Smile Again, Kyuhyun's Hope Is A Dream That Never Sleeps (OST songs are always really nice) and can I count in Eunhyuk's solo song "Down" in SS3? xDD Generally though, KRY never fails to impress; so yeah. :D