Too many to decide from

examples below
1. Ranger/Necromancer the touch ranger (touch skills from necro class mix well with expertise)
2. Ranger/Warrior the bunny thumper (hammer skills that keep your opponent on the ground mixed with increased attack speed)
3. Ranger/Monk (basic ranger but a resurrection spell)
4. Ranger/Paragon (Barraging Go for the eye’s Spammer)
5. Ranger/Ritualist (Splinter Barrager)
6. Ranger/Elementalist (conjure flame as an example to increase damage output)
Personally Ranger / Ritualist is my favorite for a big damage (Splinter Weapon Spell mixed with Barrage is really deadly in PVE)