This is an animated gif of Homer Simpson laughing. In this particular scene (during the episode "Dog of Death"), Homer imagines what he would do if he won the lottery. i.e. becoming a person that is made out of 14 karat gold.
This is an animated reaction gif of a black woman clapping and raising her hands as if to say "Praise the Lord". I'm guessing that this is from one of those Christian TV shows. Great gif to use whenever you want to express your delight at something that has just happened.
This is an animated gif of American actor Woody Harrelson wiping his tears with money / dollar bills as he is crying. If my memory serves me correctly, this is from the movie Zombieland (2009), where Harrelson played a character called Tallahassee.
This is an animated gif of a guy walking along with his head down. A perfect reaction gif to use whenever you feel deflated or sorry for yourself. Not sure what this is from, but it kind of looks like Michael Cera (it's a bit late, so forgive me if I'm wrong / seeing things).
This is an animated gif of an elderly man pointing at his computer screen and saying "Who is a faggot? OP is a faggot!" OP stands for Original Poster. i.e. the person who started a thread on a forum board or website (4chan, for example). This has become a meme of sorts, with the assumption always being: "OP is a faggot." Note that in context, the phrase has very little to do with homosexuality.