Just hit 30 which elite to take?
In PvE, Basilisk Venom is really useless, while Thieves Guild can e pretty effective sometimes (even if the cooldown is really high).
Try to get Daggerstorm asap, it is extremely good in PvE
Trixxi Is Cute – Purple Fhaz: your daily roamer
I would say thieves guild would be the most useful. It will allow you to solo more powerful mobs pretty quickly.
What race have you chosen?
If you level alone killing solo/duo mobs quick > Thieves Guild. (easier vs veterans)
If you AoE kill a lot > Dagger Storm.
I’d say Thieves Guild is probably more useful overall while leveling. It’s a good cooldown to use when you need the extra DPS and CC. Daggerstorm is a great skill, but more so in WvW than elsewhere as the ability to tag in zergs and the projectile reflect are what really make it stand out.
You should have plenty of AoE options as a Thief, with either the Sword, the Shortbow or various Bleed-spaming builds, so AoE should not be an issue. That’s why Daggerstorm won’t really be such a great asset.
if you die to range a lot: DS
otherwise: TG
Basi when nothing else useful, or someone gifts you Lyssa’s.
thieves guild.