I think a watermark looks good, done tastefully. Not a bright red blob of text over the subject's face. That said, I've never watermarked any of my pictures. None of 'em would be good enough to steal. xD
Generally speaking, I like watermarks because they let me find more pictures done by that person.
facebook // tumblr
Want to help create a US anime convention map?
PM me your local conventions to add to the map
COSPLAYS IN PROGRESS
Soren (Fire Emblem Radiant Dawn) - 3%
Vaati (LoZ Minish Cap) - 2%