Guild Wars 2

It would be nice if skills that apply a condition could be defined out of combat as to what condition they use. It would open the door for more skill types as well.
Imagine a selection set similar to how you select utilities, only it would be for your #2 through #5 skills. Such as Bladetrail (#4 GS Warrior). Instead of cripple, you could choose, instead, to have it apply poison, weakness, or burning.

For Rangers, “Hunters shot” (LB #3) could be changed to weakness, stealth, poison, cripple, etc. (which ones would be up to Anet, but I’d suggest a wide variety for more build variation).

At the same time, implementing new utilities that allow people to diminish or completely ignore a given debuff would provide an excellent counter. If you have, for instance, a theif who has double daggers completely stacked for poison on all skills, an elementalist with a anti-venom utility would only need to fear the theifs base damage. A well rounded Engineer, using various debuff options for his skills, who enters battle with all utilities set to resist fire, would be in deep trouble against a warrior using a full set of chilling skills (yes, I know, anybody is in trouble going against a warrior in the first place, it’s just an example). After respawning, the engineer, out of combat, could instantly change to raise chill resistance to improve his chances the next time he runs across that warrior (unless the warrior switches his skill flavors)
In PvE, this also allows you to choose your attack types for various mob types. Going against earth elementals? Use a utility that reduces or defeats cripple if you don’t like their initial attacks.

This would, additionally, bring food back into the spotlight, because instead of new utilities, it’s possible that food items could be used to create the resistances and anti-venoms, etc.

There are pros and cons to the idea, but it’s just a general concept for how to bring more variety into the game in both PvP and PvE combat.