It's a shame that we'll probably never get anymore sports activities. All about these big Aircraft updates but never anything simple like skateboarding, playing basketball or hitting baseballs at the batting cage.
I was thinking GTA could put it's own spin on the Baseball batting cage by having grenades shoot out of it along with the balls after a while. The player having to avoid hitting them or you'll get blown up and fail the activity which wont be as easy as it sounds due to the machines firing speed going faster as time goes by. Could easily be a fun pvp activity that gets you some cash and rp.
As for Basketball it could be turned into like a Survivor mode kind of thing where you and a crew get to shoot hoops but periodically have to stop and take out a wave of A.I gangs looking to come at you via Drive by or on foot. Most of us seen scenes like this in gangster movies so it fits if you ask me. Especially in the urban communities of Los Angeles which is what this games city is partly based on.
Of course there could be regular versions of these sports as well to just play for fun too.
For skating it should be just that. Getting to ride a skateboard down the streets of Los Santos hop up on a rail and grind across it. Do all types of tricks, etc. Back in the day Rockstar had a game called Thrasher: Skate and Destroy.
Could possibly use these controls again with upgrades.
Trick competitions, races that include bikes, roller blades and roller skates much like the old extreme games.
but nah they'd rather give us more helicopters with big bombs on it.