i like the yellow one much better. it pops more, plus i like the 'beast mode' font better as more of a computer font. actually, if you did a computer font in a cheesy 80's style, as you might find here : Computer Fonts - 1001 Free Fonts , i'm wondering how that would look. i'm thinking the computer font might fit better with the overall mien of the shirt ~ hard to say without seeing it first.
not a fan of the red beast mode, it just doesn't fit with my conception of the design. that's just me. 