(edited by ipvrf.7420)
Alt Aholic since Beta Weekends
Warrior would be the one that best meets all those requirements. It might not be the best for the WvW requirement but that seems pretty low priority.
Dungeons: Warrior
Open world farming: Ranger or Necro
Completionist: mesmer, portal, stealth and tele are boss in jumping puzzles and explorer things
WvW: thief
Delayed content is eventually good. Rushed content is eternally bad. ~ Shigeru Miyamoto
I have to agree with Khisanth, Warrior is definitely what you’re looking for.
I know a lot of people say they’re boring but I have more hours played on my Warrior than all my other characters combined and I’m still having fun with him.
Hope this helps you out! 
I have to agree with Khisanth, Warrior is definitely what you’re looking for.
I know a lot of people say they’re boring but I have more hours played on my Warrior than all my other characters combined and I’m still having fun with him.
Hope this helps you out!
Well in their “defense” some people also seem to think GS/Rifle is the only weapon set available for a warrior. In that situation I would have to agree with them because the GS animation is pretty boring to look at.
zerk all three with CoF first set and ruby jewels.
I play all 3. Thief 80 (my main for the game), Warrior 80 (strong in RP), and Mesmer 52.
Thus far the Mesmer is by far the most fun and versatile in PvE. Only my guardian is tougher to kill in a fight. Mesmers are apparently desired in dungeons as well.
I admit I do GS/Rifle on my Warrior, mostly because it suits her RP style, and because in leveling it did make me pretty tough. I don’t really PvE with her these days. My Mesmer doesn’t even have RP, I’m having so much fun leveling her even without it that I am amazed. Usually I need story driving my characters to engage my interest.
Give them all a whirl for a bit, see what appeals to your style the most.