Thought I would start a post with some of my ideas for better grouping experience. Please add yours!
-LFG tag above players head (like the current team # one)
-2 LFG tag varriants, quest and mission
-a reward for helping others with their quests* (see below)
-all members of the group see all other group members quests (a tab'd quest window)
-the group leader can select a quest and will be displayed for the whole team
-all group members should be able to see the current quest goal star/arrows on the map
-better combining of quests, some optional system where if 2 or more players in the group have the same quest they can "combine" theirs with the current quest if its the same
-basically make quests more like missions in terms of being grouping friendly
*Group Reward for Quests:
This is the biggest issue (IMO) right now - there is very little incentive to help others with their quests as they cannot be combined (doing the same quest 6 times, once for each member, is not all that fun) and on top of not really being able to tell what is going on (unless you also have the quest) there is no reward. It doesn't have to be a lot - 10% to 25% of what ever the reward for the quest is. Right now the only time people really seem to group up outside of missions (where this bascially already exists) is when travelling from town to town.
Its unfortunate but being a MMO style game and being on the "internet" people will only do things that generally net them a reward for their efforts (this isnt everyone, but most). Drops/gold are there but too crazy random and you can get them with henchmen anyways.
c

