I played since the start of beta and i found only few team funny actions. I will try to describe it here, i hope my memory will not fail me.
1) PvP. There are many kinds of PvP. Huge battles (40+ players), normal battles, suicide (mostly
) attacks, hit and run attacks, hit and hide attacks, caravan traps, caravan traps breaking, turnbased fights, "ares type" events,.. In current game mechanism, i must have at least 100 hp if i want to survive first enemy burst with minigun type of weapon. I think, that enemies can burst 2-3x with their guns per "turn". So this kind of action is forbidden for me, because with current experience system, i will have enough level to join this in june. (i still need to get my gear,...). This is not crying, this is statement of fact. I must add, that VSB reinvented guerilla attacks last era, when our players, poor equiped, defended city against enemy CA and best weapons formations. This kind of fights were almost best fights in last era, in my chart of battles are in same positions like huge Klamath 15+ minutes long fights. But seriously, the chance of wining is very small and all of us had lvl21 combat chars.
My little solution: disable (or reduce) experience decreasing, if your char is not logged for some time (days, weeks). Set this reduction to smart level, so regural players will have still big advantage against players like me, which will spend only few hours per werrk ingame. From my point of view, i will have motivation to stay ingame and i will have chance to make up for lost time in case of my character leveling.
2) PvE. There is not many PvE occasions. I know, there was one cave quest added, but not random one, so if you do that, you dont need to repeat it again (i think that it is not entertaining to repeat same quest again and again). In VSB, there were caravan hunting PvE actions last era, until developers reduce the amount of LSW in one caravan. They wanted to balance economics (they did not succeed), but they ruined the PvE action, because after that, there was better to hunt it alone because of number of LSW. Sometimes, i went with friends to caves, hunt there deathclaws and looking for some stuff. I dont know, if this is possible now. Also team centaurs/floaters hunting was team action i remember, but it was not fun, it was duty because of leveling.
3) Quests. I dont think that name quest is correct for that kind of NPC interaction. Most of them are only for first few levels to get first gear and experience, little of them are for more than one player. There is not backgound story, because (i think) that developres dont think about adding it. There is not any RPG quest, with many tipes of conversation topics, possibilities of actions and consequence in gameworld.
I.E.: Raiders: I can join raider faction, after that, i am unable to get to most cities, because everybody will attack me on sight (raiders will still attack me in encouters too :/ ). But, why is not raider "gang" something like combination of player faction and NPC faction. There can be organized raids on cities with players and NPC every (2nd, 3rd,...) day, only depends if you can find enough players, with ranks depending on kill/death ratio, number of finished actions,... . You will also get some experience points from succesfull raids, stuff (maybe stuff from encounters, where raiders were succesful). Also, you will have possibility to join encounters on the side of raiders, so i can spend my 2-3 hours per week with raider city attacks/encouters attacks and i will be satisfied. Yes, it will be easiest way how to exist in fonline (because of bad karma in cites), but it will hold many players ingame and there is disadvantage of bad karma = you cant vist cites.
Also, i am little sad. I suggested Nuclear waste storage quests and there were many similar suggestions from another players/GMs. My suggestion needs only to create little new map cca 20*20 hex which you can conncect with existing caves using green exid grid hexes. This kind of actions will be exactly that i need to return for few hours a week.. i will make char, which will be useful for team. Not pure PvP char, but scientist/thief/demoexpert/repairman/spokesman/doctor/scout ..... neccesary to succes in this kind of repetable quests. This will allow me to join this team action. I could choose from kind of chars depending on my time avaibility. It is sad, because devs every wipe wants to modify game economics and after last wipe you add many new maps (mining,..), more bigger that one map i needed (one map with random content or more very similar maps) only for mining.
4) GM organized events. It is not magnet for me, if i am not ingame. But i have one idea.. Why not to combine the NPC quests with existing players/GMs. I.e., King of Wasteland, Vedaras I. Latvian (hope your bro is healty again) can be one link in existing quest chain. I think that many players will join this kind of quests because of fun.
5) Using game client as special kind of chat aplication ("NCR chat client")