1) Any fics that deal with the fact Loki pretty much tried to kill himself when he let go, or any that deal with him being suicidal in general. Or any in which he just doesn't value his own life. Or even fics along a similar vein that don't specifically deal with that, but sort of have the same feel.
2) Fics in which he works with/helps the good guys (especially Bucky, Sif or Thor) while still technically a villian and of his own free will. (Meaning, not a slave to the Avengers or something like that.) For example, Road to Nowhere by Lise or Revelations by astolat or even What Grows Beneath the Nettle by Lizardbeth.
Thanks in advance! :)