RAC good points: the patrol will do his best to fix your car,as he will be under pressure to fix your car,and not put it up for a recovery
Bad points : time to get to you, 90mins is the norm;they have very few trucks themselfs,so if you have a 4x4 they will have to get a contracter in to do the recovery.Their vans and trucks do not go out of there area, 60 miles due to tacho laws,so again they will have to get a contracter to do the job.

AA good points:they too will do there best to fix the car,they also have more patrols.
Bad points:they have more members than anyone else,so at busy times they may take longer to get to you

Green Flag good points: they use local garages/contracters,so should be quicker at getting to you.If you have full cover they will take you home no problem as they will get paid more
Bad points:Not all garages/contracters carry diagnostic equipment

Europ Assistance,Mondial Assistance,Britannia rescue and the others same as Green Flag