Guild Wars 2

1. Melee attack assist (WvW)

Make this default option and unable to uncheck this. I think this will change game mechanic a lot and make WvW tactics more advanced and complex.

2. Guild vs Guild Wars (GvG)

Create a option for two guilds to declare war, members that are representing those guilds will fight other guild members anywhere on the map (out of main towns). If some members don’t wanna fight and need to quest and be out of combat they can stand down or represent other guild.

Also there can be a ingame statistic about kill count and war history.

This will work even better with Guild alliance.

3. Duels (PvP)

Simple, just make duel option posible.

4. Open World objectives (PvE)

Place some forts, towers and camps in open world and make them posible for other guild to tag and guard. While guild is holding some of those objects guild bank will fill with some gathering materials and coins, same as some influence. Make some live events with npc that will attack those objects with siege weapons and as time pass number of enemy will increase and it will be harder to hold that point.

You can create a various type of objects (small, medium, large) that way small guild can take camp or small tower while large guilds can hold forts or castle. Large objects will create more income then small but it will take more people to guard and hold those objects.

This way you will make some maps that are empty more atractive to high level players and fill them so they will be live once again.

5. Map portals are bad for RP game

Disable portals and bring ground mounts ingame, you can create Asura zeppelins that can carry passengers trough the maps. This will make players feel the open world and live in that world.