Some guys can be covered in tattoos and look great and pull off the look. Others could have one or two designs that look subjectively bad. It's all one's preference.
If there are any taboo locations for tattoos it would probably be the face, but even that I think is waning, as they are more accepted.
I have tattoo on one of my pecs, and love it. Once you get one, I definitely notice everyone else's tattoos to see if I like their design and placement.