Guild Wars 2

As the title says whats more useful?

Guardian (any build, heal/zerk/condi) or a revenant?

Depends on the other 9 players …
If there are no healer then go as healer (rev may be better at that), if you only have 1~2 cond then go as cond (guardian is better imo), if you have a healer and 3~4 conds then go as zerk guard/rev