For the fast-moving high DPS thiefs of Guild Wars 2, the Daredevil specialty stands out far above the others. Daredevils boast mobility, crowd control, buffs, conditions, self-healing, and strong tools for melee and ranged combat. Depending on what type of content you want to run, you can find a different specialization.
Dungeons: Dagger and Shortbow Daredevil
Use daggers and shortbows to blow through dungeons with high DPS and the ability to stealth or teleport past many annoying sections of hard dungeons. You can also use offhand pistols, though you have less access to skips. Take Withdraw or Channeled Vigor for your healing ability, Assassins Signet, Fist Flurry, Shadow Refuge or Shadowstep for your utility ability, and Dagger Storm for your elite skill.
Raids: Boon Daredevil: Raid build
For raids, you can run a dagger build similar to the dagger DPS build described above, but for best results, you should focus on boons. Using Signet of Malice, Smoke Screen, and Impact Strike, you will provide invaluable utility to your teammates. If your team needs more DPS, you can also focus more heavily on critical strikes, at the risk of needing better support from other teammates.
World vs World: Staff Daredevil
Daredevils that use staffs are extremely versatile damage dealers in organized PvP. You will be able to take over using your evasion and crowd control to disrupt the enemy. Basilisk venom and devourer venom are the key components of your kit, setting your team up for game-ending combos.