Warrior or Guardian
They both have a place in the meta, so play whatever suits your style.
PvE:
I am not too familiar with this. But I think both provide great party support and dish out nice dps. The support from warrior is more passive while the ones from guardian is more active. So it might require a bit more awareness to play the guardian
PvP:
Meta for warrior is shout bow. Super strong survivability and party support, decent 1v1 potential when holding a point. Pretty much the go-to option for the team support.
You also have ham bow as a second option which provides a lot of control and damage while still very tacky..
For guardian, the meta is meditation. It is the pinnacle zerker build that beats pretty much all other zerker specs. Super strong burst damage and good control if you pick hammer. The down side is that it does not have too much sustain. You need to be careful with your engagement. You won’t be able to beat some of the better sustain class 1v1.
The other build is the altruism bunker. It provides boons for allies while bunker down the point yourself. But you may as well just play shout bow warrior if you like support role.
WvW:
In a zerg environment, warrior provides control, condition cleanse and most importantly banner to rezz the allies. Guardian is the backbone of every organized zerg, providing important boons and have both melee and range dps.
Warrior is also great for solo roaming, GS provides one of the best mobility in the game. Medi guardian can also roam but to a lesser degree. You probably want a reliable party to roam effectively.
I play both. Neither is better than the other it comes down to personal preference. I prefer Warrior because I like the larger HP pool but they are equal on almost every front.
80 Human Elementalist 80 Sylvari Necromancer
Henge of Denravi