Deathmatches are pretty good mate

A few ways to rank up:

- get a wanted star by killing or blowing up cars and quickly drive into los santos customs when the stars are blinking to get 100 rep for each star you have.
-Get a friend and place a bounty on him/her and keep killing them for rep.
-Try racing "quick getaway" with yourself or a friend after 4 mins of racing you can get like 1800 rep and cash.

unfortunately all the good glitches and exploits are patched. I been searching everywhere since they nerfed all the rep giveouts.

Youtube:

[ Register or Signin to view external links. ]

There a new way on how to gain RP now. It'll take awhile, but it works. You have to have a friend in your lobby just one or more, then set a bounty on him, and kill him. Repeat that and you should gain a good amount of RP.

A way i've been doing for good money and fast RP is by doing the Coveted mission. If you go to the botton of the hill and steal the cargobob the mission only takes about 3 minutes. It gives you 12K$ and about 2000 RP. Best way to get money/rp now imo.