I recently noticed lelreset mention that he found out he could just hold a key to skip a cutscene in Drive-By, so I researched a bit on this.
The following are most (probably not all) places where holding a key will result in a frame perfect action, saving the precious frames with absolutely no effort.
1 - Phonecalls
Every time CJ is answering any phonecall, you can hold enter vehicle to skip it. However, the key must be held after CJ starts the phonecall answering animation. This also applies for phonecalls you get during cutscenes - I mention these in the missions section
Video:
2 - Race menus
You can hold sprint to instantly start a race. (Also to restart race) You can hold sprint + left to instantly start the previous race. You can hold sprint + right to instantly start the next race. You can hold enter vehicle to instantly quit out of the menu.
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3 - School menus
Can hold sprint to start the lesson.
Video:
4 - Gyms
Can hold enter vehicle on any gym equipment to start working out Can hold enter vehicle to quit out of any gym equipment Can hold sprint to select a level on the equipment, can also hold either up or down to start the hardest or second easiest difficulty, respectively Can hold Y (conversation positive) to start the gym fight
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5 - Cranes
Can hold enter vehicle to get in or out of cranes
Video:
6 - Vending Machines
Can hold enter vehicle to buy from vending machines (doesn't work if sliding)
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7 - Eating menus
Can hold left or right to switch the food Holding sprint will do nothing - be sure to release sprint as soon as possible for quicker eating Holding enter vehicle will do nothing - be sure to release enter vehicle as soon as possible to cancel the menu quicker
Video:
8 - Missions (I'm not recording all of these, test it out yourself)
Nines and AK's
- Can skip the cutscene/phonecall near the end by holding enter vehicle
Drive-By
- Can skip the cutscene right before the shootouts by holding sprint
Cesar Vialpando
- Can skip the cutscene that gives you the Savannah by holding sprint
- Can skip part of the cutscene at the meeting by holding sprint (will skip to the "So you think you can lowride" dialogue)
- Can trigger the bet menu faster by holding sprint, however must release and press sprint again to trigger the next part, so it's probably faster to just spam sprint here
Los Sepulcros
- Can skip the cutscene before the wall climb by holding sprint
Home Invasion
- Can drop the crates off by holding enter vehicle. Only faster if you use the crate slide, as otherwise you'll drop the crate. (Probably requires some practice to figure out optimal turning point)
Catalyst
- Can skip the cutscene where the Ballas show up by holding sprint
Robbing Uncle Sam
- Can skip the cutscene before entering the compound by holding sprint
- Can skip the final cutscene by holding sprint
The Green Sabre
- Can skip the phonecall by holding enter vehicle
Tanker Commander
- Can skip the initial cutscene (Hand over the takings, or I blow your fucking balls off!) by holding sprint
- Can skip the final cutscen by holding sprint
Local Liquor Store
- Can skip the initial cutscene by holding sprint
Body Harvest
- Can hold enter vehicle to skip phonecall
King in Exile
- Can hold enter vehicle to skip phonecall
Deconstruction
- Can skip cutscene after the initial cinematic by holding sprint
- Can skip the cutscene that shows the toilet by holding sprint
Photo Opportunity
- Can skip the cutscene by holding enter vehicle
Jizzy
- Every single cutscene except the start of mission cinematics can be skipped by holding sprint
Mountain Cloud Boys
- Can skip the cutscene near the gate by holding sprint after the cutscene triggers
Ran Fa Li
- Can skip the cutscene after entering the Manana by holding sprint
Amphibious Assault
- Can hold enter vehicle to plant the bug as soon as possible
Ice Cold Killa
- After skipping the cinematic at Jizzy's place, can hold sprint to skip the cutscene where Jizzy runs out
- Can skip the final cutscene by holding enter vehicle
Yay Ka-Boom-Boom
- Can skip the phonecall at the start by holding enter vehicle
- Can skip the cutscene at the car bomb pick up by holding sprint
- Can hold shoot to trigger the bomb as soon as possible
New Model Army
- Can hold sprint to skip the tutorial right after initial cinematic
Zeroing In
- Can skip the cutscene where Zero tells you about cell phone signals by holding sprint
Customs Fast Tracks (Video: )
- Can enter the crane by holding enter vehicle
- Can hold sprint to skip each of the cutscenes during the crane segment
- Can exit the crane by holding enter vehicle
Interdiction
- Can skip the cutscene after all enemy helis are destroyed by holding sprint
Fender Ketchup
- Can skip the cutscene in the garage by holding sprint
Explosive Situation
- Can skip the cutscene after you hit the marker at quarry entrance by holding sprint
- Can skip the cutscene after collecting all sticks of dynamite by holding sprint
- Can skip the final cutscene by holding sprint
Madd Dogg
- Can skip the cutscene after the initial cinematic by holding sprint Can skip the final cutscene by holding sprint
Architectural Espionage
- Can skip the cutscene after destroying the vents by holding sprint
- Can skip the cutscene after taking photo by holding sprint
Key to Her Heart
- Can skip the cutscene at Caligula's by holding sprint
- Can skip the cutscene in front of the store by holding sprint
- Can skip the cutscene before the master kill by holding sprint
Dam and Blast
- Can plant the charges by holding enter vehicle
Breaking the Bank at Caligula's
- Can hold enter vehicle to use all swipecards
- Can skip all skippable cutscenes inside the bank by holding sprint
Home Coming
- Can skip the final cutscene by holding sprint
Grove 4 Life
- Can skip the final cutscene by holding sprint
Good job. :)
Tanker Commander: The cutscene after attaching the trailer to the ... whatever it is.
For exclusively sprint-skippable missions in cars you should bind a third sprint key that is not also a handbrake key; because that slows you down and prevents you from exiting the car. Cutscenes that can be skipped like cinematic cutscenes cannot be skipped by tertiary sprint, use LMB for those - again, if CJ is in a car.
This might avoid the "you already have this haircut issue" but I doubt it (hold W and mash sprint). If you get it, tell us please.
The GTA:SA community has been deteriorating over a long period of time. Many top runners are not currently present on the leaderboard. This issue has not been seriously addressed yet, but an attempt will be made to remedy it now.
As of this news post, the San Andreas leaderboard will function in