In order for me to say what your next tattoo should be, I would have to know what the rest look like/will look like. I think you should worry about getting all your tattooes to agree with each other.

I don't like the blue in Croos 2. It looks a little girly. Cross 1 looks cool.

Knot 2 looks pretty bad. Don't get that one, for the love of God.

As for other suggestions, I don't know what to say about that. I don't know what your into. Im seriously contemplating getting multipe videogame themed tattoes.