This is the top 5 moments of what I think are the best moments of Arrow season 4 so far as of the mid-season finale.
5. Sara's Resurrection
Arrow killed off Sara in the first episode of last season. In season 4 Laurel decided to bring her back and put her in the Lazarus pit. It worked but she came out without a soul and was pretty insane. Constantine brought her soul back and then Sara left to go of to Legends of Tomorrow.
4. Oliver Queen's Son
It took them 4 seasons but they brought Oliver Queen's son onto the show. Oliver got a piece of his sons hair to do a DNA test to find out if it was his son. It was in fact his son and Felicity found out and they almost broke up but Barry ran back in time and started this over.
3. Constantine is back
Constantine was brought into Arrow after the cancellation of his show. Oliver needed his help restoring Sara's soul and he owed Oliver one after he saved him on Lian Yu. Constantine told him to leave the city because of Damien Darhk but Oliver doesn't really listen and runs for mayor.
2. Arrow/The Flash Crossover
The whole crossover was awesome so even though some of it took part in The Flash it still goes on the list. From the introduction of Hawkman to Hawkgirl getting her powers, it was all around awesome. Vandal Savage appeared in Central City to wreak havoc so The Flash needed to Arrow to keep Hawkgirl safe and to help stop Vandal Savage. In the end they destroyed Vandal Savage and Hawkgirl left with her reincarnated soulmate (Hawkman).
At the end of Arrow's mid-season finale Oliver proposed to Felicity and she said yes. The drove off in a limousine which was then shot at by Darhk's men. It ended with Oliver holding Felicity in his arms while she was bleeding out. Is she dead? Is she the one in the grave? She could be. Arrow returns January 20 so we will find out then.
Is there anything I left out? Leave it in the comments.