When I just started SA-MP when it was very popular I used to love freeroam servers to play on with RL friends, team up as a cop and make a block on the road with police cars and try to kill criminals. After my freeroam experience I went to a small (20 - 30 players) RPG server (not pure roleplay), it was more like freeroam with a great community organizing RPG events but whatever, it was called Pug's Real Life, this was when it just got launched.
After a small break with SA-MP I came back and joined the server RPG Streetlife, another RPG server but a little more RPG and less freeroam, still a fun server. I stay(ed) here for a long time and that's when I found out about ''hardcore'' roleplay servers (a la The Godfather / Sin City / Valhalla Gaming) and I enjoyed them and I've been playing on a lot of RP servers since then.
Still I prefer the more fun Freeroam RPG servers with a great community and great gangs, this is in my opinion the best roleplay to have since you don't get helped by all the tools a full RP script has, you need to use your imagination a lot, it's hard to maintain this on a server and you need to have a GREAT and solid community to achieve this, when you do it's a great experience.
I never really got into stunting, it's just not cool in my opinion and I don't like to do it.
I voted roleplay though since I just like to, my second choice is freeroam.