Ghost Easter Egg
To me, this is a very interesting Easter Egg, because it has a story to it. This Easter Egg is about the ghost of Vinewood actress, Lenora Johnson, who was murdered. You can collect 50 letter scraps to solve the mystery. You can also go to the location shown below and wait until 23:00, and see her ghost. If you approach it, the ghost will disappear, and you can see the words, "Jock" written in blood.
Hatch From "Lost" Easter Egg
The hatch fthat some believe is from the show "Lost" is located at the location shown in the picture below. Since it is underwater, I would recommend getting scuba gear from the Sonar Collections Dock. Once you approach the hatch, you will hear Morse Code which decodes: "Hey, you never call, how d'you fancy going bowling?" Roman Belic from GTA 4 would often call you and say this.
The story mission Hood Safari takes players back to Grove Street, the old stomping grounds of GTA: San Andreas protagonist CJ and the rest of the Grove Street Families. A lot has changed over the years, but Rockstar couldn't pass up the opportunity to slyly reference their previous work. Just as you turn onto Grove Street itself you'll see characters that look almost exactly like CJ, Big Smoke and Sweet ride by on bicycles.
No Country For Old Men
Off the interstate at the Northwest portion of the map, you will find people acting out the movie No Country For Old Men. For your troubles, you will get $25k.
Max Payne
If you purchase Michael a goofy looking Hawaiian shirt, get the free " The Wood " haircut, and put on a pair of Rimmers Steel Aviators, he closley resembles Max Payne from Max Payne 3.
John Marston is Your Online Dad
In GTA Online, one of your parents can be John Marston, the main character in another Rockstar title, Read Dead Redemption.
Read Dead Novelized
In Franklin's Vinewood Hills home, one of the books on the bookshelf in his room says, Red Dead by J. Marston.
Tapdancing Hillbilly
In the wilderness, you will find a tapdancing hillbilly, which is a reference to the real life tapdancing hillbilly, Jesco White.
Madd Dog and OC Loc
In Franklin's home, you will find records of two rappers from GTA San Andreas, Madd Dog and OC Loc.
Brucie Kibbutz
Infamous GTA 4 character, Bruice Kibbutz has a website where he sells performance enhancing drugs, and also makes appearances in the online portion.
Random Mountain Face
There is a random face textured into one of GTA's mountains. People say it's Jessie Pinkman from Breaking Bad.
Mystery 8 Killer
The Mystery 8 Killer is one of GTA 5's more cool and elaborate easter eggs. Graffiti found all over GTA 5's world seems to be left by the killer himself, each creepy sing-songy rhyme leading to yet another clue and hinting at yet another murder. A final message sends players to cellblock 9A in GTA 5's otherwise underutilized prison. A newspaper clipping found near the first clue states that the serial killer died in prison. But did he really?
Blueprint Map
In the GTA 5 Collector's Edition Box, there is a map that once is exsposed to a black light, messages on the map can easily be seen.