Left Boy - Dangerous : Makes me think of Matt with Alex 
[youtube]https://www.youtube.com/watch?v=_h9V94b4R2g&list=PL3SBfmoq22eLA2OvtPYC9rirp2MPXwVjS&index=2&t=0s[/youtube]

Weezer - Hero : I feel like this will fit Daniel when he realizes how he kinda ended up as the villian when he decided to help Matt.
[youtube]https://www.youtube.com/watch?v=ob3iZzAmBeI&list=PL3SBfmoq22eLA2OvtPYC9rirp2MPXwVjS&index=4[/youtube]

All Time Low - Some Kind of Disaster : I picture this also fitting Daniel (and kinda Alex) when they start falling for each other despite both of them lying and trying to use the other lol
[youtube]https://www.youtube.com/watch?v=ZLTkSUCq1u8&list=PL3SBfmoq22eLA2OvtPYC9rirp2MPXwVjS&index=5[/youtube]

Jeremy Zucker - somebody loves you : This one I think will fit Daniel almost perfectly when he realizes that his sister likes Alex too and is struggling with both his feelings and the whole mob thing xD
[youtube]https://www.youtube.com/watch?v=EtJAX-W_1EA&list=PL3SBfmoq22eLA2OvtPYC9rirp2MPXwVjS&index=9[/youtube]

FINNEAS - Let's Fall in Love for the Night : I feel like this one just fits them lol Mainly coming from Daniel's POV, especially with how they first met haha
[youtube]https://www.youtube.com/watch?v=yua-rAyVvmY&list=PL3SBfmoq22eLA2OvtPYC9rirp2MPXwVjS&index=8[/youtube]