I would like SG missions with SG rewards.
The missions would be long, story-arc type missions that could require multiple teams in multiple places over, possibly, multiple days. The reward for completing the mission could be access to special, SG costume options, minor, non-combat temporary powers, access to new stores, or access to instanced hunting areas.
I would like SG v SG competition.
A SG could start of series of missions linked with another SG's series of missions. Based how one SG acts in one set of missions, the other SGs mission could change. For example, SG bashes up a Council base to get a clue. When SG2 goes to investigate Council, they find security has been beefed up due to recent raids.