Fight or Flight
So, you have a wanted level and are being chased by the cops. What are your options?
Fight
If you are feeling lucky, you can take your chances at killing the pursuing officer.
⚠ Warning: shooting an officer that isn't chasing you could be considered RDM, please refer to the rules when thinking about starting a fight.
Officer on Foot
If the officer is on foot and running towards you, you can take a weapon appropriate for the range and shoot them. If the cop is hiding behind a car, try to shoot the fuel tank or engine to easily explode it.
Officer in a Car
If the officer is in a land vehicle, your best bet is shooting at one of the tires and making the officer crash or alternatively shooting them, watching out for any possible ramming.
Officer in an Aircraft
If the officer is in a helicopter or a plane, a good idea is always shooting at either the rotor or engine respectively, as aearial vehicles are very prone to damage in these locations.
Flight
A fun way to get rid of the police is to flee. If you are a non-violent criminal, it's better for you not to shoot when escaping the police, as they cannot attack you unprovoked. Shooting will significantly increase the chances of dying, especially when you are being chased by multiple cops.
On-foot Chases
It's time to get your parkour skills ready! The best way to outrun cops when you are on foot is to find high places and take dangerous jumps. If the cop is in a car and you are on foot, you can jump at the right moment before he rams you; you should also find undestructible objects such as walls and poles, and again, high grounds from where they can't hit you.
Hot Pursuits
San Andreas has many tunnels, bridges and roads in which you can escape from the police; and if you are on a hardcore server you can even hide. Be careful, while it's not very common, some cops use spike strips to puncture your tires.
Surrendering
When asked to freeze or pull over by a police officer, you have the choice to hold X to surrender.
This is different from just putting your hands up (press X), because when you surrender, your character will be forced on its knees and you can no longer control it until you are arrested or the cops leave/die.
If you have illegal items, this is by far the least favorable option that you can opt for, as it's almost guaranteed that you will be searched and your items will be confiscated.
Choose this option when you lost all hope, maybe they will not kill you and you will save on hospital bills. Maybe they will be even kind enough to offer you a bribe.
Bribing
Usually you want to abstain from bribing random players, especially ones with a low level or from enemy crews.
If however, you trust the officer you are bribing, you can walk up to them and offer them money for your freedom, you can only bribe with cash, so make sure you always have some withdrawn.
Be wary if a cop is on foot though, as they can easily cuff you when you stand near them to bribe. If they are in a car, tell the cop to stay in to avoid that risk; alternatively, stay in your car and ask them to walk up to you.
Bribing the police is not available if you are a Most Wanted Suspect.
Committing Suicide
Finally, as a last resort, you can kill your character intentionally to avoid falling in the hands of the police. This is only a choice when the police are not accompanied by paramedics, because paramedics can simply prevent you from respawning, revive you, and hand you over to the police officers in handcuffs.
Usually drug dealers will choose this option, and they will do it by intentionally taking an overdose amount of their product. If you are unlucky, the police officer could be equipped with Naloxone, which is an antidote to drug overdoses, and they will be able to stop your suicide, apprehend you and confiscate your drugs.