may i add more?(continuing miromiro's post)
26. Do stunts on a car with nitrous
-Get a sports car(i prefer turismo, buffalo, bullet, super gt, cheetah, infernus, banshee etc) then perform an alley oop(one i know is near the las venturas sign going to the desert)
27. 6 star survival
-Make sure to have at least 2 star wanted levels. Lure the police to wang cars. Make sure you have a heat seeking RPG/Minigun with a sh-tload of ammo. Now start blowing sh*t up until you get 6 stars. If you get 6 stars, grab a car from wang cars. Instead of going to the nearby PnS, joyride instead. If the car blows up, use a minigun then keep on shooting at police vehicles!
28. NRG fun
-Like attempting to spin by holding the down arrow button.
29. Trespassing into Area 69
-Grab a rustler(if you only completed learning to fly with bronze) or a stunt plane(if completed learning to fly with silver) then fly to area 69 with a very low altitude, crash into the ground, bail out. Your plane explodes. Now steal a tank then either stored it to verdant meadows immediately or have fun first with the tank. After you are done having fun with the tank, you may store the tank now inside the hangar.)
30. Having danger with a jet plane(shamal or hydra)
-Fly in low altitude. Do some stunts.
31. Rioting in Casinos.
-Start a gunfire. Guards will come after you. Kill them until you have 6 stars.
32. Jetpack drive by
-Have a pistol and/or a Machine Pistol(make sure your weapons are hitman for dual wielding) then start killing cops/peds until you have 6 stars.
33. Monster donuts
-It says it all. Hold the handbrake button then start ramming peds by doing the donuts.
34. Truck shooting
-Jump on the truck's rear. Use an AK-47/M4/SMG then start doing riots.
35. 4 star vortex fun
-Somehow similar to Vice City Stories mission "From Zero to Hero". Since the vortex is considered more as an aircraft government Hydras will start shooting at you. Evade the rockets as possible!
36. 5 star using a Sanchez
-Trespass to Easter Basin Naval Station. You will get a 5 star wanted level. Get out of the Naval Base and (if you dated Michelle) go to her pay 'n' spray and lose your wanted level by using a Sanchez bike.
37. 6 star fun with an invisible car
Type the wanted level cheat 3 times and the "WHEELSONLYPLEASE" cheat. Then have fun with a 6 star wanted level on an invisible car.
38. Spaceeinstein's All-In-1 mod fun
-All the fun that you need are in his mod. Search it on google.
39. RPG fun
-Use the Soviet's famous RPG then keep on blasting sh*t.
40. Gang wars using a Jetpack.
-Start a gang war using a Jetpack. Again you need a pistol or a machine pistol.
41. Spray can riot
-Obviously you need a spray can. Start a riot by killing a cop using a spray can
-Another way to kill boredom. Good places to find myths are in Smoke's crack palace, the Panopticon or Back O Beyond.
That's all I can add.