Well for PVE, I would say Dark Warrior or SK with PVE build.
They are tankers, high LP, good dmg, and you can heal a little.
Turtle is good but you need kame for that and pray that your kames won't fail.
If they fail, you die.
Crane is good in pve too, if you want to be evil enough and with right build ofc, still they are way better in pvp.
Dende - OP healer, he is need in every party, only thing that sucks is his low dmg but that is why he have OP healing.
Poko - have speed, healing and have dragon pets that can help you in pve.
Every class can be used in PVE, just some class are way better in pve than others.
I would say go DW or SK for PVE, because of their survivability.