Artifact Implants

[Xenonia]

Needs negative effects, too:

Leeches health until removed
Randomly teleports user around
Makes user center of gravity, making items frequently hit them
Change user's subrace to Martian/Illithid/Dwarf
Cause the user to fatten then explode

And some more good ones:

Laser-vision
Health HUD implant
Ghost vision, can see ghosts
Healing touh: Can heal others by shaking them with help.